TPS-2 Portable Photosynthesis
System
Operator’s Manual
Version 2.01
© 2006 PP Systems. All Rights Reserved
30th January 2007
Europe
PP Systems
Unit 2, Glovers Court, Bury Mead Road.
Hitchin, Hertfordshire, SG5 1RT, U.K.
Tel: +44 1 462 453 411
Fax: +44 1 462 431 090
North America
PP Systems Inc.
110 Haverhill Road, Suite 301
Amesbury, MA 01913 U.S.A.
Tel: +1 978 834-0505
Fax: +1 978 834-0545
Email: [email protected]
Web Site: http://www.ppsystems.com
This page is left intentionally blank.
Table of Contents
Table of Contents
Table of Contents...........................................................................................3
Preface............................................................................................................5
Notice............................................................................................................5
Documentation Conventions .........................................................................5
User Registration ..........................................................................................5
Service & Warranty .......................................................................................6
Contact Information.......................................................................................6
Unpacking Your Equipment ..........................................................................6
System Calibration........................................................................................7
System Notes................................................................................................7
Technical Specifications ...............................................................................8
Measurement Theory...................................................................................10
TPS-2 Main Console ....................................................................................12
Battery Charging Socket .............................................................................12
Keypad........................................................................................................12
LCD Display ................................................................................................13
Gas Analysis Connections ..........................................................................13
Serial (RS232) Data Connection.................................................................13
Leaf Cuvette Connection ............................................................................14
Absorber Columns ......................................................................................14
Soda Lime ........................................................................................................................ 15
Envirogel........................................................................................................................... 15
Material Safety Data Sheets (MSDS)............................................................................... 15
Powering Up The TPS-2 ..............................................................................16
Menu Structure.............................................................................................17
Measurement of Leaf Gas Exchange..........................................................17
1REC ..........................................................................................................17
Recalculation Software Based On Leaf Area................................................................... 19
Measurement Mode ....................................................................................20
System Checks Prior to Making Measurements .........................................21
Recording a Measurement ............................................................................................... 22
How do I know when the leaf is at equilibrium in the leaf cuvette?.................................. 22
Controlling CO2, H2O, and Light (LED) .......................................................22
CO2 Control ...................................................................................................................... 22
H2O Control ...................................................................................................................... 23
Light Control (LED Light Unit Only) .................................................................................. 23
Using The TPS-2 As A Stand-Alone CO2/H2O Analyzer .............................24
2CAL...........................................................................................................25
CO2 Calibration ................................................................................................................ 25
CO2 Calibration Using A Gas Cylinder ............................................................................. 25
H2O Calibration ................................................................................................................ 27
PAR Sensor Calibration ................................................................................................... 27
Setting the PAR Sensor Gain and Offset Constants........................................................ 28
LED Calibration ................................................................................................................ 28
1 Point Calibration Check................................................................................................. 28
LED Scale......................................................................................................................... 30
10 Point Calibration .......................................................................................................... 30
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Table of Contents
LED Initialization............................................................................................................... 31
3DMP..........................................................................................................31
SCREEN DUMP............................................................................................................... 31
4CLR...........................................................................................................32
5CLK...........................................................................................................32
6DIAG .........................................................................................................32
1:DIAGNOSTICS.............................................................................................................. 32
2: INITIALISE.................................................................................................................... 34
Data Output ..................................................................................................34
Data Output During Measurement ..............................................................34
Data Output of Stored Records From Memory ...........................................35
Transfer/Logging Software .........................................................................36
Transfer of Stored Data ..............................................................................36
Logging Data ..............................................................................................36
Maintenance .................................................................................................38
Air Sampling Pump .....................................................................................38
Air Sampling Pump Replacement .................................................................................... 38
Cleaning The Air Sampling Pump .................................................................................... 38
Air Inlet Filters .............................................................................................39
12V Lead Acid Battery ................................................................................39
EPROM.......................................................................................................39
Absorber Columns & Desiccants ................................................................40
Soda Lime Specification................................................................................................... 41
Envirogel Specification ..................................................................................................... 42
Error and Warning Displays........................................................................45
TPS-2 Photosynthesis Calculations...........................................................47
Symbol Definitions ......................................................................................49
Measured Parameters...................................................................................................... 49
Calculated Parameters..................................................................................................... 50
Physical Constants Used In Equations ............................................................................ 50
Derivation of Saturated Vapour Pressure of Water (bar) from Air Temperature.............. 51
Technical References....................................................................................................... 51
Corrections to Stomatal Resistance Measurements For Differing Transpiration Rates
Under Upper and Lower Leaf Surfaces............................................................................ 51
TPS-2 Portable Photosynthesis System Operation Manual Revision Log
.......................................................................................................................55
User Notes....................................................................................................56
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Preface
Preface
Notice
This equipment must not be used in situations where its failure could result in injury or death.
For applications where failure of this equipment to function correctly would lead to
consequential damage, the equipment must be checked for correct operation and calibration
at intervals appropriate to the criticality of the situation.
PP Systems' equipment warranty is limited to replacement of defective components, and
does not cover injury to persons or property or other consequential damage.
This manual is provided to help you install and operate the equipment. Every effort has been
made to ensure that the information contained in this manual is accurate and complete. PP
Systems does not accept any liability for losses or damages resulting from the use of this
information.
It is extremely important that you take the time to review this Operator’s Manual prior to
installation and operation of the equipment. Otherwise, damage may be caused which is not
covered under our normal warranty policy.
This manual, and the information contained in it, is copyright to PP Systems. No part of the
manual may be copied, stored, transmitted or reproduced in any way or by any means
including, but not limited to, photocopying, photography, magnetic or other mechanical or
electrical means, without the prior written consent of PP Systems.
Windows and Excel are registered trademarks of Microsoft.
Quattro Pro is a registered trademark of Borland
Lotus 1-2-3 is a registered trademark of Lotus.
MS-DOS is a registered trademark of IBM.
Documentation Conventions
If viewed electronically, text marked blue acts as Hyperlinks.
User Registration
It is very important that ALL new customers register themselves with us to ensure that our
user’s list is kept up to date. If you are a PP Systems’ user, please register yourself
electronically on our web site at:
http://www.ppsystems.com/Register.html
Only REGISTERED users will be allowed access to our protected “Users” section of our web
site. This section will contain important product information including hardware/software
updates, application notes, newsletters, etc.
Thank you in advance for your cooperation.
TPS-2 Portable Photosynthesis System Operator's Manual – Version 2.01
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Preface
Service & Warranty
PP Systems' equipment warranty is limited to replacement of defective components, and
does not cover injury to persons or property or other consequential damage.
The equipment is covered under warranty for one complete year, parts and labor included.
This, of course, is provided that the equipment is properly installed, operated and maintained
in accordance with written instructions (i.e. Operator's Manual).
The warranty excludes all defects in equipment caused by incorrect installation,
operation or maintenance, misuse, alteration, and/or accident.
If for some reason, a fault is covered under warranty, it is the responsibility of the customer to
return the goods to PP Systems or an authorized agent for repair or replacement of the
defective part(s).
Contact Information
Europe
PP Systems, Ltd.
Unit 2, Glovers Court, Bury Mead Rd.
Hitchin, Herts SG5 1RT
UK
Tel: (01462) 453411
Fax: (01462) 431090
Sales:
Support:
Service:
USA & Canada
PP Systems, Inc.
110 Haverhill Rd, Suite 301
Amesbury, MA 01913
USA
Tel: 978-834-0505
Fax: 978-834-0545
[email protected]
[email protected]
[email protected]
Unpacking Your Equipment
It is extremely important that you check the contents of your equipment immediately upon
receipt to ensure that your order is complete and that it has arrived safely. Please refer to the
checklist supplied (if applicable) for a detailed list of spares and accessories that are included
with your order.
DO NOT DISCARD ANY OF THE PACKAGING MATERIAL UNTIL ALL OF THE ITEMS
LISTED ARE ACCOUNTED FOR.
WE RECOMMEND THAT YOU RETAIN THE ORIGINAL PACKING FOR FUTURE USE.
If you suspect that any of the items listed on the appropriate checklist are not included or
damaged, you must contact PP Systems or authorised distributor immediately.
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System Calibration
•
•
•
This product is shipped as a factory calibrated system. System calibration is not
required upon receipt from our factory.
Familiarization with the documentation and calibration procedures is required prior to
future recalibration. See section 2CAL on page 25 of this manual.
All calibration related questions may be made directly to PP Systems at:
Telephone: +1 978.834.0505
Fax: +1 978.834.0545
Email: [email protected]
System Notes
We strongly urge that each user read this manual at least once before getting started.
It is also very important to observe the following notes in order to avoid accidental
damage to TPS-2.
•
Never connect the TPS-2 to a battery charger without the internal battery fitted to the unit.
•
Only use the battery charger supplied by PP Systems.
•
The 12V battery charger can power the TPS-2 and charge the internal battery at the
same time.
•
Before changing any absorber columns, please refer to the appropriate section of the
manual. The location of the columns can be found on the bottom of the TPS-2 main
console.
•
The TPS-2 AND WATER DO NOT MIX, so do not use water bubblers or manometers
with your system or use the TPS-2 in conditions where water may be drawn into the unit.
•
Never connect the TPS-2 direct to a gas cylinder. Connection must always be via a Tpiece or Y connector with one leg connected to the cylinder, one to TPS-2 and the third to
the atmosphere through about 30 centimetres of pipe. (A flowmeter may be used to show
there is surplus flow but never use a water bubbler).
•
If the TPS-2 does not start up when switched on, or if the pumps start but there is no
display, check that the battery is fully charged.
•
In case of queries, please quote Eprom version and TPS-2 serial number. This
information is displayed when the TPS-2 is first switched on. In addition, the serial
number of the TPS-2 main console can be located on the bottom of the instrument.
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Technical Specifications
Technical Specifications
Main Console
Analysis Method
Non-dispersive infrared, configured as an absolute absorptiometer with microprocessor
control of linearization.
Measurement Range
CO2: 0-2,000 µmol mol-1 (Optimal Range)
0-9,999 µmol mol-1 (Max. Range)
H2O:
0-75 mb
Corrections are made for temperature, pressure and foreign gas broadening.
Precision (Absolute)
CO2: < 1% at 300 ppm
H2O: < 1% at 100% RH
Stability (CO2 Analysis)
Automatic Zero at regular intervals, corrects for sample cell contamination, source and
detector ageing and pre-amplifier gain changes.
Control Range
CO2: 0-2,000 µmol mol-1 ( 6 steps)
H2O: 0- Dewpoint (4 steps)
Response Time
Electrical: 0.5 seconds
Display/Analog Output: 1.6 seconds
Pneumatic: < 5 seconds
Air Sampling
100 cm3 min-1 using an integral DC pump.
RS232 Output
Stored/current data output in standard ASCII format at 1200 baud.
Real Time Clock
Accuracy: Better than 1 min/month at 25o C.
Operating Temperature: 0-70o C.
Recording Options
By PC or by the instrument. Automatic logging at user selectable intervals between 10
seconds and 1 hour, controlled by internal real-time clock.
Power Supply
Internal, rechargeable 12V battery providing up to 8 hours continuous use.
Integral Cuvette Air Supply Unit
0-500 cm3 min-1 measured and controlled by a mass flow meter.
Operating Environment
0-50o C, non-condensing. In dirty environments, external air filtration is required.
Housing
High impact ABS plastic case.
TPS-2 Portable Photosynthesis System Operator's Manual – Version 2.01
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Technical Specifications
Dimensions
29 cm W x 12.5 cm H x 20 cm D
Weight
5.2 kg.
PP Systems is continuously updating its products and reserves the right to amend product
specifications without notice.
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Measurement Theory
Measurement Theory
The TPS-2 is a completely self-contained unit for measuring the CO2 assimilation
(Photosynthesis and Respiration) and transpiration (water loss by evaporation of leaves of
plants. It has been designed specifically for use by students in Schools and Universities. It
offers many of the facilities of instruments designed for research (e.g. Ciras-1), but greatly
simplifies the measurement procedure.
It operates on the “Open System” principle. The leaf is placed in a sealed enclosure with a
window for illumination. This is referred to as the leaf cuvette. Through the cuvette is passed
a measured flow of air. The CO2 / H2O concentrations of the air entering (reference air) and
of the air leaving (analysis air) are measured. To measure the concentrations the TPS-2 uses
a single CO2 and H2O sensor and alternately switches the reference and analysis air. From
the flow rate of air and the change in the concentration the assimilation and transpiration rates
are calculated.
Though it is designed to supply ambient air to the cuvette, for the study of CO2 responses, it
is possible to decrease the CO2 concentration in a series of steps. A similar provision is made
for water vapour responses. It is supplied with a leaf cuvette which can be used for a wide
variety of leaves. A light unit will be available shortly (LED) for use with the cuvette for manual
control of cuvette light intensity.
CO2 /H2O Analysis Measurement Principles
Carbon Dioxide absorbs Infra-red radiation strongly at a wavelength of 4.26 microns. TPS-2
uses this absorption to measure the CO2 concentration. The analyzer consists of a source of
infra-red radiation (a small tungsten filament lamp) at one end of a highly polished, gold
plated tube through which the air passes. At the other end of the tube is the infra-red detector
which has a window through which only infra-red radiation at 4.26 microns can pass so that
the responds only to the presence of CO2. The theoretical analysis range is from 0-100%
CO2. However, because of the absorption characteristics of gases, the absorption path
lengths, infrared source intensities, detector sensitivities and the S/N (Signal to Noise) ratio of
the system define the effective range. The absorption path length of TPS-2 is optimised for
2,000 volumes of CO2 per million volumes of air. This is correctly referred to as 2000 parts
per million by volume or 2000 ppm. (Ambient air contains about 360 ppm.).
Temperature corrections are not required as the opto-electronics are thermostatted and the
air is equilibrated to this temperature before entering the absorption cells. The built in
transducer compensates for absolute pressure changes in the cell.
In part, the excellent stability of TPS-2 is due to regular zeroing when CO2 free, air is passed
through (referred to as ZERO). ZERO minimises the effects on span (gas sensitivity), of
sample cell contamination, source ageing, and changes in detector sensitivity, amplifier gains,
and reference voltages. It is done every approximately minute. The ZERO reading is used to
compensate for changes in the signal level. From the relationship between absorptance and
concentration, determined in the factory, and the current calibration factor, the sample
concentration is determined.
Water vapor is measured using a high precision capacitive sensor. This consists of a small
piece of glass coated first with a layer of metal, then with a polymer, followed by a second
metal layer. Wires are soldered to the metal layers and the sensor is placed in a circuit that
measures its electrical capacitance. The amount of water in the polymer depends on the
water vapour content of the air and the electrical capacitance of the polymer depends on the
water content. So with calibration, the water in the air can be measured. Water vapour
concentration is again expressed as a volume/volume relationship but in parts per thousand,
which is called millibars (mb).
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Measurement Theory
Both CO2 and H2O measurements give the absolute concentrations for the reference air, and
then the difference between the reference and the analysis concentration.
The complete TPS-2 gas circuit with control valves is shown below.
Le af
Cuvette
Ai r S up ply H2O
Pu mp
Va lve
CO2
Va lve
H2O A bsor ber
Moisture E xch ang er
CO2 A bsor ber
Ve nt
REF/AN
Va lve
Zero
Va lve
Sa mple
Pu mp
Ai r
In
H2O
Se nsor
CO2 IRGA
Ai r
Ou t
CO2 A bsor ber
The normal operating position of the TPS-2 is with the key board/display on the upper
surface(referred to as the TOP) and with the absorber columns on the side of the instrument
away from the user.(referred to as the FRONT). For field measurements, the TPS-2 main
console should be housed in the in the custom field carrying case with the shoulder straps
adjusted as required for most comfortable operation.
There is a slide switch to the left of the keypad. The legend shows which direction to slide the
switch to turn the instrument on or off.
The TPS-2 is powered from its own internal 12V battery, or from an external power supply
that is simultaneously recharging the internal battery, or from an external battery.
The internal battery is a 12V 7.0Ah sealed Lead-Acid battery. The exact running time of the
battery will depend on its state of charge; its capacity (this declines with age); and the
ambient temperature (determines the power requirement of the thermostatted cells). The
battery is located inside the instrument.
THE INTERNAL 12V BATTERY MUST ONLY BE CHANGED AFTER THE TPS-2 HAS
BEEN TURNED OFF.
During operation, when the battery voltage drops to 10.5V, the TPS-2 will put up a low battery
display and, if ignored, will automatically close down shortly after.
If TPS-2 does not start up when switched on, check the battery.
ONLY USE THE BATTERY CHARGER/POWER SUPPLY SUPPLIED BY PP SYSTEMS AS
THIS HAS THE CHARGING VOLTAGE SET FOR OPTIMUM OPERATION.
TPS-2 Portable Photosynthesis System Operator's Manual – Version 2.01
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TPS-2 Main Console
TPS-2 Main Console
Battery Charging Socket
The battery charger input socket is located directly below the ON/OFF slide switch. It
features a single phono jack connection for the battery charger. The system is supplied with
the appropriate charger and connector. Please ensure that the charger plug is fully inserted
into the charger socket when charging the TPS-2.
Keypad
Press Key
0-9
Y
N
0/R
4/X
To
Enter a numeric value.
Accept (Yes) a display/value and move forward to the next
display.
Terminate (No) an operation.
Record the displayed data in memory when in the measurement
mode.
Toggle (Exchange) from one display (measured data) to another
(calculated data) in measurement mode.
All key presses should be firm and the user should wait for the instrument to respond. When
a menu shows a series of options, pressing the corresponding key to the number opposite an
option changes that setting. This may require entry of numeric data (e.g. recording interval)
or may just change the option (e.g. recording type). Where numeric data is required, then a
series of ?? corresponding with the number of digits required will be displayed. Leading
zeroes should be entered where necessary (eg. ???? followed by entry of 0500 for 500 ppm).
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TPS-2 Main Console
LCD Display
The LCD display has 2 rows of 16 characters. To the left of the display is a small hole that
gives access to a potentiometer controlling the display contrast. This can be adjusted with a
screwdriver. At high temperatures, the display gets darker and may ultimately be unreadable,
though TPS-2 continues working.
IT IS RECOMMENDED THAT AT HIGH AIR TEMPERATURES WITH HIGH RADIATION,
TPS-2 IS KEPT SHADED.
Gas Analysis Connections
There are four gas pipes arranged on left hand side of the TPS-2.
The top pipe is where a sample of the reference air flowing to the leaf cuvette may be taken
out. When TPS-2 is being used with the cuvette, a pipe should link this to the next entry down
marked REF.
REF is the inlet pipe to the reference line of the analyzer. For a smoother supply of reference
air, we strongly recommend linking this inlet to the inlet directly above (Link For PLC). The
instrument is supplied as standard with a link pipe already fitted. For calibration, the
calibration gas should be connected via a T-piece direct to this entry.
The following two gas pipes are used for connection to the leaf cuvette.
AN/PLC A is the inlet pipe to the analysis line of the analyzer. The pipe marked A on the leaf
cuvette returning the analysis air from the cuvette should be connected to this.
PLC R is the cuvette air supply outlet. The pipe marked R on the leaf cuvette taking the
reference air to the cuvette should be connected to this.
A link pipe is also fitted on the front of the TPS-2 console (near absorber columns) for
additional smoothing of the reference air (see markings on the bottom of the TPS-2). When
linked, the internal TPS-2 enclosure acts as a smoothing volume. If you prefer to sample the
air further away from the instrument, you can remove the link pipe here and connect a long
piece of piping directly to the Air Supply Inlet only. Important Note. If you connect
directly to the Air Supply Inlet, you must make sure that the sampling point is far away
from any CO2 disturbing influences and it MUST NOT be near liquid water.
Serial (RS232) Data Connection
The PC computer connection is the 9 pin D socket on the front panel marked RS232. An
RS232 data transfer cable is supplied with each system.
Only 2 pins are used :9-Pin D Socket (on TPS-2)
Pin 2 – Transmit Data
Pin 5 – Digital Ground
9-Pin D Plug (on PC)
Pin 2 – Receive Data
Pin 5 – Signal Ground
RS232 Serial Data Format
Baud Rate
Start bit
Data bits
Stop bits
Parity
4800
1
8
2
None
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TPS-2 Main Console
**** WARNING ****
Only the pins specified should be used, as other pins may have dedicated functions
and damage may result if these are connected to ground, supply or any inappropriate
load.
Leaf Cuvette Connection
The leaf cuvette is connected to the 15 pin D socket on the front panel marked PLC. The
following pins are used:
Pin 1
Pin 3
Pin 5
Pin 7
Pin 9-15
5V reference voltage. This must not be used for purposes other than
connecting to the Betatherm 100K6 type thermistor. (See Pin 5).
PAR input. 0-1V = 0-3,000 µmol m-2 s-1
Air Temperature Thermistor. A Betatherm type 100K6 thermistor is connected
between here and Pin 1 to correctly read the temperature.
+12V supply (unregulated at battery voltage)
Return (0V)
The PLC D-type connector and can only be inserted in one position. Visually locate it and
present the connector to the TPS-2 socket in the correct position. Push the connector firmly
home and secure in place.
To remove the connector, pull upwards on the plug. It is essential to pull upwards on the
plug and not on the cable.
For more information on the leaf cuvette, refer to its own operator’s manual.
Absorber Columns
The TPS-2 is fitted with 4 absorber columns. Each absorber contains desiccants for the
controlling/absorbing of CO2 or H2O. With TPS-2 in its normal upright operating position and
going from left to right, the absorber columns are:
1
Column
1
2
3
4
Desiccant
Soda Lime
Envirogel
Envirogel
Soda Lime
2
3
4
For:
CO2 Control
H2O Control.
H2O Control
Auto-Zero Control for CO2 analyzer
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TPS-2 Main Console
Please note that the bottom of TPS-2 clearly indicates the layout and contents of all 4
absorber columns for reference purposes.
For further information regarding replacement/handling of absorber columns and chemicals,
refer to Absorber Columns & Desiccants on page 40.
Soda Lime
Soda lime is used to remove CO2 from air entering the TPS-2 for zeroing the analyzer and for
control of CO2. It is supplied as self-indicating granules (1-2.5mm) which turn from green to
brown as they become exhausted. The contents of the absorber column should be replaced
when it is approximately 2/3rds exhausted. Soda Lime cannot be regenerated and should be
discarded after exhausted.
Envirogel
Envirogel is silica gel with an indicator (orange changing to green) used for drying the air.
However, it can be regenerated by heating in an oven if necessary (above 100° C but not
exceeding 150° C). It is non-hazardous and can be easily disposed of when exhausted.
**** CAUTION ****
WASH YOUR HANDS AFTER HANDLING SODA LIME AND ENVIROGEL
Material Safety Data Sheets (MSDS)
For the latest safety related information on all desiccants used with our products, visit our
website at http://www.ppsystems.com/Literature/MSDS/index.html .
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Powering Up The TPS-2
Powering Up The TPS-2
Before switching the TPS-2 on, please make sure of the following:•
If the TPS-2 is to be used with the leaf Cuvette, make sure the cuvette is properly
plugged in (electrically) before power up. The TPS-2 will automatically detect if the
cuvette is connected when turned on.
•
Check that the reference and analysis pipes of the leaf cuvette are properly fitted to the
corresponding ports on the TPS-2 and that the necessary TPS-2 pipe links are in place
as required.
•
Check the condition of the chemicals in the absorber columns and replace if necessary
(see Absorber Columns on page 14).
•
Horizontal operation of the instrument could result in air being drawn across the surface
of the absorbers rather than through them. The instrument should therefore always be
used at an angle sufficient to prevent this from happening. The recommended position is
vertical with the display and keypad on top.
•
If the LED light unit is to be used, ensure that it is fitted properly to the cuvette head and
electrically connected to the cuvette. Remember to perform a one point calibration check
prior to measurements (see 1 Point Calibration Check on page 28).
Immediately after switching on the TPS-2, a copyright statement is displayed, which also
shows the instrument and the program version number installed. This should be quoted in
any queries.
After about 7 seconds the Main Menu should be displayed. (If either CHECKSUM ERROR or
MEMORY CORRUPT, see Error and Warning Displays on page 45).
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Menu Structure
Menu Structure
After the initial messages are displayed as described in the previous section, the Main Menu
will be displayed as follows:
1REC 2CAL 3DMP
4CLR 5CLK 6DIAG
Options are selected by pressing the appropriate key. After selection, pressing key N will
return you to the Main Menu.
Measurement of Leaf Gas Exchange
1REC
For purposes of this manual, we are assuming that you are using a leaf cuvette with the
TPS-2 for measurement of leaf gas exchange. Therefore, all leaf gas exchange parameters
are measured, displayed and recorded by the TPS-2. After selecting 1REC, the next four
menus that are displayed are used to set up the system configuration. After
checking/changing any of the system configuration data, a “Y” keypress will advance you to
the next menu.
Please Note. If a leaf cuvette is not used and the TPS-2 is being used as a stand alone
analyzer, only 2 of the following menus (Menu 2 without FLOW rate and Menu 4) will be
displayed before entering the Measurement Mode. After selecting 1REC, the message “NO
CUVETTE ANALYZER ONLY” message will be displayed.
From the Main Menu, press key 1 (1REC) for selection of leaf cuvette:
Menu 1
SET PLC 1:BROAD
2:UNIVERSAL
Press Key
1
2
To
Instruct the TPS-2 that you are using our PLC4 (B) broad style leaf
cuvette. For all new TPS-2 users, this is the style cuvette being
supplied with all instruments. This cuvette has a round chamber with
a diameter of 18mm.
Instruct the TPS-2 that you are using our older PLC (U) or PLC2 (U)
universal style leaf cuvettes.
It is very important to select the appropriate leaf cuvette. Each cuvette has slightly different
characteristics (i.e. cuvette window, location of PAR sensor, etc.). The TPS-2 measurements
and calculations will be based on the cuvette selected here. If you have any questions as to
which cuvette type you have, contact PP Systems ([email protected]) by email and
provide us with the serial number of your cuvette.
After selecting the cuvette, the next three menus display the current configuration of the
system.
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Menu Structure
Menu 2
1REC:M 2INT: 0
FLOW:300
Press Key
1
2
To
Toggle between automatic (A) and manual (M) recording. For leaf
gas exchange measurements, we recommend manual recording so
that measurements can be recorded when the leaf reaches
equilibrium.
To set the automatic recording interval. If automatic (A) recording is
selected, press key 2 (2INT) to set the recording interval (1-250)
minutes). If manual (M) is selected, 2INT is set to 0 by default.
Note, remember to use leading 0’s when entering the recording interval. For instance, an
entry of 002 is required for an automatic recording interval of 2 minutes.
The cuvette flow rate (FLOW) is set to 300 cm3 minute by default and can not be changed.
Press Key “Y” to advance to the next menu to select the light source used and to set leaf
area:
Menu 3
1: LIGHT = SUN (or LAMP/LED)
2: LEAF AREA = 02.5
Press Key
1
2
To
Toggle between Sun or Lamp/LED. If natural sunlight is used for
measurements, press key 1 until SUN is displayed. If you selected
“Universal” for the leaf cuvette, you have the option for selecting
“Lamp” if using our quartz halogen light unit. For measurements
using the quartz halogen light unit, press key 1 until LAMP is
displayed. If you selected “Broad” for the leaf cuvette, you have the
option for selecting “LED”. For measurements using the LED light
unit supplied with the PLC4 (B), press key 1 until LED is displayed.
Proper selection of the type of light source used is required to set the
value of the constants (i.e. TRANS factors) used to convert PAR
(Photosynthetically Active Radiation) measurements to the energy
absorbed by the leaf. It also sets the defaults for the boundary layer
and leaf area for the cuvette.
Set the projected leaf area (cm2). We recommend entering a value
as close to the actual value as possible. To assist in determining leaf
area, the total window sizes for our cuvettes are as follows:
•
•
•
PLC (U) Universal Leaf Cuvette: 10.35 cm2
PLC2 (U) Universal Leaf Cuvette: 4.5 cm2
PLC4 (B) Broad Leaf Cuvette: 2.5 cm2
For most accurate leaf gas exchange measurements, the actual area
should be determined after measurements are made using a suitable
leaf area meter. All data can be recalculated based on actual leaf
area using a simple “Recalculation” program offered by PP Systems.
See below.
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Menu Structure
Recalculation Software Based On Leaf Area
When using the TPS-2 Portable Photosynthesis System, there may be cases when the actual
leaf area is not known at the time of measurement. Accurate leaf area determination is
very important in the final calculation of photosynthesis and other calculated
parameters. When this is the case, the leaf area entered in the TPS-2 setup menu should be
a good estimate. Typically, after measurements are completed and for greatest accuracy, it is
highly recommended that leaf samples are measured to determine the true leaf area using a
suitable method (i.e. portable leaf area meter, image analysis, etc.). For accurate results, the
data previously collected by the TPS-2 will need to be recalculated based on the true leaf
area measurement of each sample. The TPS-2 Data Recalculation Software Program can be
used for this purpose.
When data files are transferred to the PC from the TPS-2, two file types are created,
‘File.ORG’ and ‘File.DAT’. The ‘File.DAT’ file format is where the data is separated into
appropriate real values with signs and decimals points. Commas separate the values, which
makes the data suitable for spreadsheet applications. The ‘File.ORG’ file format simply
outputs a continuous data string. There are no commas, signs, or decimal points. This is
how the original data is stored in the TPS-2 internal memory. It is not suitable for
spreadsheet applications or the TPS-2 recalculation software program.
Recalculation software and instructions are available to all registered users from our web site.
If you are not registered with us, we strongly encourage you to do so by clicking:
http://www.ppsystems.com/Register.html
Press Key “Y” to advance to the next menu for selection of plot number and to view the
number of records available for storage:
Menu 4
1P:01 R:01
FREE RECORDS 820
Press Key
1
To
Set the plot number which is used to identify stored records. To
change the displayed value, press key 1 and enter the desired value
(1-99).
R refers to the record number associated with the plot number. This
is reset to 1 when the plot number is changed and increments up to a
maximum value of 89. Note, this will recycle to 1 after the 89th record
is taken.
FREE RECORDS refers to the the number of records that can be taken before the memory is
full. The maximum number of records that can be saved is 820.
Press Key “Y” to advance into the Measurement Mode.
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Menu Structure
Measurement Mode
The next operation depends if this is the first entry into the record mode since the TPS-2 was
switched on. Upon first entry, the analyzer temperature is checked. Checking continues until
the set temperature is approached. Once the temperature is stable (approximately 54o C),
the analyzer starts making and displaying measurements but these will not be valid for up to 1
minute until the analyzer has done a zero cycle.
If there is a re-entry into the measurement mode, then measurements will immediately be
displayed. If the TPS-2 is switched off then quickly turned on again then, at this stage, the
following message may be displayed for a short period as the TPS-2 checks itself.
<GETTING DATA PLEASE WAIT>
Then the display will show measured data :
Cnnnn +/-nnn Qnnnn
Hnn.n +/-nn.n Tnn.n
Where:
Top Row
C
+/-nnn
Q
Lower Row
H
+/-nnn
T
Reference CO2 concentration (ppm). Range: 0000-9999.
Differential CO2 concentration (ppm). This is the difference between
the air entering the leaf cuvette (reference) and the air leaving the
leaf cuvette (analysis).
PAR (µmol m-2 s-1). Range: 0000-2,500. If LED is selected in Menu
3 described earlier, Q will display the LED lookup table value. If SUN
or LAMP is selected, the corrected PAR sensor reading is displayed.
Reference H2O concentration (mb). Range: 00.0-75.0.
Differential H2O concentration (mb). This is the difference between
the air entering the leaf cuvette (reference) and the air leaving the
leaf cuvette (analysis).
Cuvette temperature (oC)
To view the calculated data associated with the measured data (including user inputs
described earlier), press the 4/X key:
Enn.nn Gnnnn Tnn
A+/-nn.n CInnnn
Where:
Top Row
E
G
T
Lower Row
A
CI
Evaporation rate (mmole m-2 s-1).
Stomatal conductance (mmole m-2 s-1).
Leaf temperature (oC) based on energy balance.
Assimilation rate (µmol m-2 s-1).
Internal CO2 concentration (ppm)
Every 4.8 seconds, both measured and calculated data are transmitted out of the RS232 port
and can be viewed on the PC if required. To do so, connect the serial cable provided with the
system between the 9 pin “RS232” port on the front of the TPS-2 and the serial port on the
PC. Using the software provided by PP Systems (or hyperterminal on your PC), you can view
the output on the PC.
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Menu Structure
While you are in the measurement mode, the following key presses are available to the user:
Press Key
R
1
2
3
4/X
Y
N
To
Record a measurement (see Recording a
Measurement on page 22)
Change recording type (manual or
automatic). See Menu 2 under 1REC. To
return back to the measurement mode,
press key Y.
Change light type and leaf area. See Menu
3 under 1REC. To return back to the
measurement mode, press key Y.
Change the plot number. See Menu 4
under 1REC. To return back to the
measurement mode, press key Y.
Toggle between measured and calculated
data.
Set CO2, H2O and LED Control (see
Controlling CO2, H2O, and Light (LED) on
page 22).
Return to Main Menu. Note, we highly
recommend returning to the Main Menu
prior to powering down the TPS-2.
System Checks Prior to Making Measurements
Before proceeding with measurements, we always recommend performing the following
system checks (with measured data displayed) to ensure that the system is operating
properly:
With the leaf cuvette closed and connected to the TPS-2 main console as described earlier in
this manual, perform the following basic system checks:
System Checks
The reference CO2 value (C) should be stable (+/- 1ppm) and
reading the approximate set concentration. If ambient, the value
should read approximately 370-380 ppm. If the CO2 reading is
unstable, check that the area from where you are sampling from
is away from any CO2 influencing items such as vehicles,
ventilation, individuals (breathing), etc.). A smoothing volume
may be required in some cases. It may take the instrument 510 minutes to stabilize at ambient levels.
The differential CO2 value (+/-nnn) should be 000 (+/- 001ppm).
The PAR value (Q) should read the approximate value. On a
bright sunny day (with no clouds), values should be in the 1,5002,000 range.
The reference H2O value (H) should be stable (+/- 00.1ppm) and
be reading the approximate set concentration.
The differential H2O value (+/-nnn) should be 000 (+/- 001ppm).
The cuvette temperature (T) should read similar to the ambient
temperature.
Yes
No
If you have answered yes to all of the above system checks, your system is working properly
and you are ready to begin making measurements.
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Menu Structure
Recording a Measurement
To record a measurement, press the R key when either the measured data or calculated data
is displayed and after the leaf has equilibrated in the cuvette.
How do I know when the leaf is at equilibrium in the leaf cuvette?
Immediately after opening the cuvette to insert your leaf, you will notice an increase in the
differential CO2 concentration (signified by a +nnn value) as a result of outside air getting into
the cuvette? Once the cuvette head is closed and the leaf is secured by the closed cell foam
gaskets, the differential CO2 concentration will start to drop significantly and eventually begin
to go negative (-nnn) to show that the leaf is absorbing CO2 (assuming a healthy leaf). In
addition, depending on the state of the plant and its stomatal mechanisms, the differential
H2O concentration should begin to go positive (+nn.n). After approximately 30-45 seconds,
the differential CO2 and H2O concentrations should begin to stabilize. When the CO2
differential remains at a steady level for more than 4-5 seconds, it can be assumed that the
leaf is at equilibrium and a measurement can be recorded.
Immediately after pressing the R key, a message similar to the following will be displayed:
RECORD rrr TAKEN
PLOT= pp nn
Where :rrr
Number of records stored so far (up
to 820)
Current plot number
Record ID.
pp
nn
Controlling CO2, H2O, and Light (LED)
The TPS-2 offers manual control of CO2, H2O and Light (when LED light unit is used) if
required. With the measured or calculated data displayed as described earlier, press the Y
key and the following control submenu will be displayed as follows:
CONTROL SETTINGS
1CO2 2H2O 3LED
CO2 Control
Press key 1 to select CO2 CONTROL and the following is displayed:
CO2 STEP n (MAX=6)
N=CHANGE Y=OK
CO2 control can be set in steps of 6 where n is the current step (default value = 6). The
following table illustrates the approximate values of CO2 per each step:
Step
6
5
4
3
2
1
CO2
Concentration
(% of Ambient)
100
75
60
45
25
0
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Press key N to change from step to step. If step 6 is selected, then this means that there will
be no absorption of CO2 and the reference supply of CO2 to the leaf cuvette is at full ambient
CO2 concentration. If step 4 is selected, the reference supply of CO2 to the leaf cuvette will
be scrubbed (through the soda lime desiccant) so that approximately 60% of the ambient CO2
concentration is provided to the leaf cuvette and so on.
Please be aware of the following affect when controlling CO2. Sodalime is a desiccant that is
used to absorb the CO2 and this contains water which wets the air. Therefore, depending on
the ambient humidity, setting a lower CO2 control setting may result in a higher air humidity.
Press key “Y” to return to the measurement mode when completed.
H2O Control
Press key 2 to select H2O CONTROL and the following is displayed:
H2O STEP n (MAX=4)
N=CHANGE Y=OK
H2O control can be set in steps of 4 where n is the current step (default value = 4). The
following table illustrates the approximate values of H2O per each step:
Step
4
3
2
1
H2OConcentration
(% of Ambient)
100
80
60
35
Press key N to change from step to step. If step 4 is selected, then this means that there will
be no absorption of H2O and the reference supply of H2O to the leaf cuvette is at full ambient
H2O concentration. If step 2 is selected, the reference supply of H2O to the leaf cuvette will
be scrubbed (through the envirogel desiccant) so that approximately 60% of the ambient H2O
concentration is provided to the leaf cuvette and so on.
Press key “Y” to return to the measurement mode when completed.
Light Control (LED Light Unit Only)
Press key 3 to select LED for control of light intensity and the following is displayed:
LED LEVEL n=xxxx
PRESS 0-9 OR Y
Where:n
xxxx
Refers to the Level Number (0-9).
This is the last value set by the user.
Refers to the light intensity (PAR)
corresponding to Level n
(µmol m-2 s-1).
Pressing keys 0-9 will change the current level and PAR value associated with it. The user
can step through all levels to see the corresponding light levels if required. Select the light
level required for your measurements and make sure that the light intensity indicator on the
LED light unit is also set to the same LED level selected on the display.
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Menu Structure
Note, if LED is not selected in the setup menu, a message “LED NOT SELECTED” will flash
on the display. See page 18 under Menu 3. The LED light unit must be selected in order to
manually control light intensity.
Important Note
It is extremely important that you perform a simple one point calibration of the LED light unit
on a daily basis prior to the start of measurements. See LED Calibration on page 28.
Using The TPS-2 As A Stand-Alone CO2/H2O Analyzer
The TPS-2 can be used as a high precision, stand alone CO2/H2O analyzer if required. For
this application, a leaf cuvette is not used with the TPS-2. In addition, the menu structure is
different than that described earlier. With no leaf cuvette connected to the TPS-2, power the
unit up and the Main Menu will appear as follows:
1REC 2CAL 3DMP
4CLR 5CLK 6DIAG
Press key 1 to begin. A message “NO CUVETTE ANALYZER ONLY” message will be
displayed followed by the following:
1REC:M
Press Key
1
2
2INT:
0
To
Toggle between manual (M) and automatic (A) recording.
To set the automatic recording interval (1-250 minutes). If manual
(M) is selected, 2INT is set to 0 by default.
Note, remember to use leading 0’s when entering the recording interval. For instance, an
entry of 002 is required for an automatic recording interval of 2 minutes.
Press Key “Y” to advance to the next menu for selection of plot number and to view the
number of records available for storage:
1P:01 R:01
FREE RECORDS nnn
Press Key
1
To
Set the plot number which is used to identify stored records. To change
the displayed value, press key 1 and enter the desired value (1-99).
R refers to the record number associated with the plot number. This is
reset to 1 when the plot number is changed and increments up to a
maximum value of 89. Note, this will recycle to 1 after the 89th record is
taken.
FREE RECORDS refers to the the number of records that can be taken before the memory is
full. The maximum number of records that can be saved is 820 (When the memory is empty).
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Menu Structure
Press Key “Y” to advance into the Measurement Mode. When the TPS-2 is used as a standalone CO2/H2O analyzer, only the measured data is displayed and stored as follows:
Cnnnn +/-nnn Qnnnn
Hnn.n +/-nn.n Tnn.n
Where:Top Row
C
+/-nnn
Q
Lower Row
H
+/-nnn
T
Reference CO2 concentration (ppm). Range: 0000-9999.
Differential CO2 concentration (ppm). This is the difference between the
air entering the leaf cuvette (reference) and the air leaving the leaf
cuvette (analysis).
PAR (µmol m-2 s-1). Range: 0000-2,500.
Reference H2O concentration (mb). Range: 00.0-75.0.
Differential H2O concentration (mb). This is the difference between the
air entering the leaf cuvette (reference) and the air leaving the leaf
cuvette (analysis).
Cuvette temperature (oC)
While you are in the measurement mode, the following key presses are available to the user:
Press Key
R
1
To
Record a measurement.
Change recording type (manual or
automatic). To return back to the
measurement mode, press key Y.
Change the plot number. To return back to
the measurement mode, press key Y.
Return to Main Menu. Note, we highly
recommend returning to the Main Menu
prior to powering down the TPS-2.
3
N
2CAL
From the Main Menu, press key 2 to check and calibrate the CO2 analyzer, H2O sensor, PAR
sensor and LED light unit (if used).
1:CO2
3:PAR
2:H2O
4:LED
CO2 Calibration
The TPS-2 is a very stable instrument and should NOT require CO2 calibration.
However, we do highly recommend that you check the CO2 calibration regularly against a
standard source or against ambient air (away from CO2 sources such as cars, boilers, breath,
etc). For the most accurate CO2 calibration check, we recommend using a certified gas
cylinder with an accuracy of +/- 1%.
CO2 Calibration Using A Gas Cylinder
In order to carry out a proper CO2 calibration, the following items are required and must be
followed:
•
•
•
A standard gas cylinder for CO2 calibration (recommended +/- 1% accuracy).
The contents of the analyzer zero column (1) must NOT be exhausted.
The analyzer must have been switched on for at least 30 minutes.
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Menu Structure
Connection is made to the PLC R inlet on the front of the TPS-2. The gas cylinder of known
CO2 must not be connected directly to the TPS-2, but through a T or Y connector, with one
leg going to the TPS-2 REF inlet, one leg to the gas cylinder, and the third leg to atmosphere
through a 30 cm pipe. The flow rate from the gas cylinder should be set so that there is a
small excess (approx. 250 mls/minute) flowing to waste.
ON NO ACCOUNT USE GAS BUBBLING THROUGH WATER TO INDICATE SURPLUS
FLOW. IF TPS-2 INGESTS WATER, IT IS LIKELY TO SEIZE THE PUMP AND CAUSE
DEPOSITS IN THE CELL THAT WILL AFFECT THE ANALYZER LINEARITY.
Press key 1 to select CO2 calibration.
CO2 CONC = nnnn
CORRECT Y/N
nnnn is the current setting of the calibration concentration. If this is correct then press Y.
To enter the new value based on the concentration of your gas cylinder, press N and enter
the new calibration concentration. This must be between 100 and 2,100ppm. For optimal
accuracy, it should be just greater than the maximum concentration of CO2 that you intend to
use. (i.e. If you intend to always measure at ambient levels, then a calibration cylinder of
400ppm would be ideal for system calibration). NEVER calibrate with a concentration a lot
lower than the measurements levels anticipated (i.e. Do not use a 300 ppm standard when
measuring around 2,000 ppm).
On completion of the concentration selection the display will show:
CO2 CONC = nnnn
KEY0 WHEN STEADY
Next, connect the calibration gas cylinder and with the gas flowing through the T or Y piece
described above, wait until the TPS-2 gives a steady reading. When the concentration
reading is steady, press key 0. Be sure to press 0, for any other key will abort the calibration.
When 0 is pressed, “Input Accepted” is displayed and the calibration factor is calculated and
stored in memory. There should be only a second or so delay before the Main Menu is
displayed.
If the display continues to show “Input Accepted“ for a longer period:
1. Switch off the TPS-2.
2. Switch the TPS-2 on again and when the Main Menu is displayed, press key 6
(6:DIAG).
3. Press key 2 (2:INITIALISE) and when prompted with ????, enter 0462.
4. From the Main Menu, press key 2 and attempt another calibration.
If there is a significant (Say 10%) difference between the calibration gas concentration from
your cylinder and the TPS-2 reading, try the following:
1. Quit the calibration by pressing key N.
2. Check the TPS-2 CO2 zero absorber and ensure that it is fresh (green color).
3. Next, measure the outside CO2 concentration away from all CO2 influencing sources
(i.e. automobiles, ventilation, breathing, etc.). If the TPS-2 reads correctly (350380ppm) then the standard gas concentration may be suspect.
To abort a calibration at any time and return to the Main Menu, press N.
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Menu Structure
H2O Calibration
Press key 2 to select H2O calibration.
H2O MB = nn
CORRECT Y/N
nn is the current setting of the calibration concentration. If this is correct then press Y.
To enter the new value based on the actual concentration, press N and enter the new
calibration concentration. This must be between 10 and 50 mb.
On completion of the concentration selection the display will show:
H2O MB = nn
KEY0 WHEN STEADY
Next, connect the calibration source with gas flowing through the T or Y piece described
above, wait until the TPS-2 gives a steady reading. When the concentration reading is
steady, press key 0. Be sure to press 0, for any other key will abort the calibration. When 0
is pressed, “Input Accepted” is displayed and the calibration factor is calculated and stored in
memory. There should be only a second or so delay before the Main Menu is displayed.
If the display continues to show “Input Accepted“ for a longer period:
1. Switch off the TPS-2.
2. Switch the TPS-2 on again and when the Main Menu is displayed, press key 6
(6:DIAG).
3. Press key 2 (2:INITIALISE) and when prompted with ????, enter 0462.
4. From the Main Menu, press key 2 and attempt another calibration.
If there is a significant (Say 10%) difference between the H2O source concentration and the
TPS-2 reading, quit the calibration and try again. If the problem continues, contact PP
Systems.
To abort a calibration at any time and return to the Main Menu, press N.
PAR Sensor Calibration
Press key 3 to select PAR sensor calibration on the leaf cuvette.
RAW=
7COR= 7
CORRECT (Y-N)?
Both the raw PAR reading and the corrected PAR reading are displayed as above. The PAR
sensor is calibrated at the factory and under normal conditions, maintains its accuracy for the
life of the instrument. Some cuvettes that work with the TPS-2 have integral gain and offset
potentiometers on the cuvette handle that can be used to adjust the PAR readings. Other
cuvettes with no gain and/or offset adjustment in the cuvette can utilize the PAR Calibration
routine to adjust the PAR readings to match a customer’s laboratory standard or another PAR
sensor reading.
The PAR readings are processed in the TPS-2 as follows:
COR = (RAW – OFFSET) * GAIN
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Menu Structure
Where:
RAW
COR
OFFSET
GAIN
Is the raw PAR reading directly from the cuvette.
Is the corrected PAR reading used in all calculations and data recording.
Is a user-entered constant between 0 and 200 (factory default = 0).
Is a user-entered constant between .5 and 1.999 (factory default = 1.000).
Setting the PAR Sensor Gain and Offset Constants
With the following displayed:
RAW=
7COR= 7
CORRECT (Y-N)?
Position the cuvette in a known light environment of various levels and note the two readings.
If the readings are correct, press Y to return to the calibration menu. To set the Gain and
Offset constants (or to see what they are currently set to), press N, and the following will be
displayed:
1:OFFSET 000
2:GAIN
1.000
To set the Offset constant, press 1, then a three digit number between 000 and 200.
To set the Gain constant, press 2, then a four digit number between 0.500 and 1.999.
Press any other key to return to the display of current PAR readings.
LED Calibration
Press key 4 to select LED calibration.
1: 1 POINT CHECK
2: 10 LEVEL CAL
1 Point Calibration Check
Pressing key 1 will allow you to perform a simple one point calibration (Level 7) check of the
LED light unit. If the TPS-2 is supplied with an LED light unit, PP Systems will perform a full
calibration at the factory. The calibration values are stored in non-volatile memory.
However, we still highly recommend performing a one point calibration check of the
LED light unit on a daily basis prior to measurements since it is expected to drift from
day to day. Make sure that the indicator on the LED light unit is set to 7.
Important Note
Never look directly into the light unit when it is powered on
(even at low intensities).
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Menu Structure
PAR Sensor Holder
Indicator for light
intensity adjustment
Connect electrically
to the 3 pin plug
located here.
In order to perform this one point calibration check, the LED light unit must be fitted to the leaf
cuvette. In addition, the cuvette head must be open in order to position the PAR sensor
below the LED light unit. To perfom this calibration:
1. Remove the thumb screw on the cuvette handle by turning it counter-clockwise until
loose and slide it out (See below)
Thumb Screw
2. Once the thumb screw is removed, the bottom head plate will drop down allowing
easy access below the light unit.
3. Next remove the PAR sensor from it’s holder on the side of the cuvette and hold it
steady and level in the middle of the cuvette window just below the window (see
below).
PAR Sensor
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Menu Structure
4. Assuming that the light unit intensity indicator is set to 7, wait approximately 2
minutes for readings to stabilize.
At this point:
SENSOR nnnn LEVm
TABLExxxx 1/2/3
Where:Is the actual value being measured by the PAR sensor (µmol m-2 s-1).
Refers to the Level number (7)
Is the stored value for PAR for Level 7(µmol m-2 s-1).
nnnn
m
xxxx
From here:
Press Key
1
2
3
N
To:
To keep the stored TABLE value. If the SENSOR value is similar to the TABLE
value (within 20 µmol m-2 s-1), press key 1 (or Y). You will be returned to the
main menu.
If the SENSOR value is much different (> 20 µmol m-2 s-1) than the TABLE
value. A new LED Scale factor is calculated and stored that makes the LEVEL
7 table value match the current PAR SENSOR reading. When matched, press
key 1 (or Y) to return to the main menu.
To display the current LED Scale. A new value can also be manually entered
between 0.500 and 1.999 if required. See LED Scale on page 30.
Exit to main menu
LED Scale
The LED Scale is a multiplier applied on all values in the LED lookup table. It is forced to
1.000 on initialization and whenever any 10 Point Calibration value is entered or changed.
Whenever TABLE values are displayed and/or used in the firmware for computation, the LED
Scale is applied. When satisfied with your entry, press Y to return to the main menu.
10 Point Calibration
Press key 2 to perform a 10 point calibration showing:
SENSOR nnnn LEVm
TABLE xxxx 1/2/3
Where:nnnn
m
xxxx
Is the actual value being measured by the PAR sensor (µmol m-2 s-1).
Refers to the Level number (0-9). During this process, Level 0 will be
displayed first.
Is the stored value for PAR for Level m (µmol m-2 s-1).
The steps for perfoming a 10 point calibration check are identical to the one point check
described in the previous section with the only exception being that you have to set each
individual level starting at 0 (lowest level) and continuing through to 9 (highest level). At this
point, make sure that the light intensity indicator on the LED light unit is set to 0. With the
PAR Sensor positioned level in the middle of the cuvette window just below the light unit (as
described in the previous section), note the SENSOR reading. If the SENSOR value is
similar to the TABLE value (within 20 µmol m-2 s-1), press key 1 and you will be automatically
stepped up to the next level. If the SENSOR value is much different than the TABLE value
(>20 µmol m-2 s-1), press key 2. The new SENSOR reading should now match the TABLE
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Menu Structure
value and will replace the current TABLE value for that LEVEL. Continue for all 10 levels
making sure that the light intensity indicator on the LED light unit matches the LEVEL
on the TPS-2 display for all 10 levels. After completing LEVEL 9, you will automatically
return to the main menu.
LED Initialization
The LED light unit can be set back to factory default settings if required.
Initializing the TPS-2 will force all the current table values to 0 and will require a full 10 point
calibration before entering the measurement mode. Please refer to the PLC4 (B) Operation
Manual supplied with your TPS-2 technical documentation for information on how to perform
this calibration.
3DMP
Press key 3 (3DMP) from the Main Menu to display or transfer stored records in the database.
Note, the internal records are not erased during this process.
1: SCREEN DISPLAY
2: DATA DUMP 1/2?
SCREEN DUMP
Press key 1 to view stored data on the TPS-2 LCD display starting at the most recent record:
PLOT 01 REC 01
09/03 12:19
To view the measured data associated with the displayed plot and record number, press Key
7. To view the calculated data (if a leaf cuvette is used with the TPS-2) associated with this
measurement, press Key 7 again. This key will toggle back and forth between the measured
and calculated data associated with this measurement.
To view the next most recent record in storage, press the “Y” key and the next Plot No., Rec.
No., etc. will be displayed.
Please note. Where there are 2 further displays, as for leaf cuvette measurements, the
displays will scroll around on this keypress.
Key Y
displays the next most recent record in store.
Key N
returns to the Main Menu.
All other keys are ignored.
It is therefore possible to step back through memory, searching on either date/time or values.
When all the records have been displayed then:NO MORE RECORDS
IN STORE
is displayed, followed by a return to the Main Menu.
DATA DUMP THROUGH THE RS232 INTERFACE.
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Menu Structure
Press key 2 (2:DATA DUMP) to transfer stored data from the TPS-2 to an external PC via the
serial (RS232) port. The oldest data is transferred first. The RS232 protocol and the data
format is described in the RS232 Section of the manual.
When 2 is selected, the display shows :CONNECT TO PC
ANY KEY TO SEND
After making the appropriate interface connection, make sure that the PC is ready to receive
before pressing a TPS-2 key. There is no handshake, so data will be immediately sent on the
key press.
TRANSMISSION
IN PROGRESS
is displayed during transmission, followed on completion by:NO MORE RECORDS
IN STORE
and return to the Main Menu.
4CLR
Used to clear the database. Press key 4 to clear the database and remove all previously
stored records. To ensure that this cannot be done inadvertently, several key presses are
required. Press YY and then 0 to confirm. A “DATABASE CLEARED” message will display
before returning you to the Main Menu.
5CLK
Used to reset clock to the correct time and date. Press key 5 to view the current time and
date settings. Press key N to accept the settings or key Y to change. The date is set based
on Day-Month-Year and the clock is based on a 24 hour clock (i.e. 2:00PM should be set to
14:00). The clock settings are always retained by the internal battery.
6DIAG
This is available to users but is primarily meant for testing and maintenance.
After pressing Key 6 the display will show :
1:DIAGNOSTICS
2:INITIALISE
1:DIAGNOSTICS
Press key 1 to view system diagnostics. These are the 16 bit readings of the A/D converter
measuring the CO2 Infra-red sensor output in Reference / Analysis and Zero modes. The
zero should be the largest reading for without CO2 there is no infra-red absorption so the
sensor output is larger.
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Menu Structure
DISPLAY 1
CR: NNNNN A:NNNNN
Z:NNNNN
A/D read for CO2 Analyzer Reference.
This should read between 41000-43000
if working properly.
A/D read for CO2 Analyzer Analysis.
This should read between 41000-43000
if working properly.
A/D read for CO2 Analyzer ZERO. This
should read higher than the Reference
and Analysis A/D reads between
48000-50000 if working properly.
CR:NNNNN
A:NNNNN
Z:NNNNN
Press key Y to go to the next display in Diagnostics:
DISPLAY 2
HUMIDITY REF: NNN
ANALYSIS: NNN
A/D read for H2O Sensor Reference.
(Reading in % x 10)
A/D read for H2O Sensor Analysis.
(Reading in % x 10)
HUMIDITY REF:NNN
ANALYSIS:NNN
Press key Y to go to the next display in Diagnostics:
DISPLAY 3
LCT NNN
PAR
NNNN
A/D read for leaf cuvette temperature
(oC x 10)
A/D read for PAR
LCT:NNN
PAR:NNN
Press key Y to go to the next display in Diagnostics:
DISPLAY 4
RHT
ATP
RHT: NNN
ANT: NNN
ATP: NNNN
AUX: NNN
NNN ANT NNN
NNNN AUX NNN
A/D read for H2O sensor (x 10)
A/D read for analyzer temperature (x
10).
Atmospheric pressure in the analyzer
sample cell.
Not Used (Should read 0)
Press key Y to exit Diagnostics and return to the Main Menu. When stepping through the
Diagnostics menus, a key press of N will return you to the Main Menu.
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Data Output
2: INITIALISE
Before using this function, you must first download all stored data from
your TPS-2. After initialization, all stored data will be removed
permanently from internal memory.
This option is used for initial calibration of the instrument in the factory, and can be used by
the user to reset the TPS-2 analyzer calibration back to factory defaults if the memory has
been corrupted. Initialisation should be followed by a CO2 calibration, since the analyzer
should be recalibrated rather than leaving set to the factory default (see 2CAL on page 25).
To proceed with initialisation, press key 2 and when prompted with ????, enter the test code
0462. If this is correctly entered, TPS-2 is re-initialised and returns to the Main Menu.
Data Output
Data Output During Measurement
Data is continously output via the RS232 on the TPS-2 every 4.8 seconds. A complete record
consists of a single line of 67 characters (excluding space at start and <CR> at the end). For
manual purposes, a complete data string is as follows:
Character
Position
S
35
CAT
38
LAR
1
3
5
9
13
18
23
27
30
PP
RR
DDMM
HHMM
CO2RF
+CO2DF
PARM
MBRF
+MBDF
64
ATMP
<CR>
41
FLOW
45
EVAP
49
GSGS
53
TLF
56
+PNN
60
CINT
The position of each character in the string is numbered to facilitate string handling in any
user program. The following describes each variable in the transferred data record.
S
PP
RR
DDMM
HHMM
CO2RF
+CO2DF
PARM
MBRF
+MBDF
CAT
LAR
FLOW
EVAP
GSGS
GLF
+PNN
CINT
ATMP
<CR>
Space sent before first character from data string is transmitted.
Plot number (00-99)
Record number (1-89)
Date (Day and month)
Time (Hour and minutes)
Reference CO2 concentration (ppm)
Differential CO2 concentration (ppm)
PAR (Photosynthetically Active Radiation) as measured by PAR sensor on leaf
chamber (µmol m-2 s-1)
Reference H2O concentration (mb)
Differential H2O concentration (mb)
Leaf Cuvette Air Temperature (oC)
Leaf Area as entered by the user (cm2)
Flow rate measured by the internal mass flow meters (cm3 min)
Calculated transpiration rate from the leaf (mmole m-2 s-1)
Calculated stomatal conductance (mmole m-2 s-1)
Calculated leaf temperature (oC)
Calculated assimilation rate ((µmol m-2 s-1). A + reading indicates
photosynthesis (CO2 uptake and a – reading indicates respiration (CO2
evolution).
Calculated sub-stomatal CO2 concentration (ppm)
Atmospheric pressure (mb)
Carriage Return (end of data string)
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Data Output
Data Output of Stored Records From Memory
The data string for stored TPS-2 data is slightly different than that described in the previous
section.
Character
Position
35
CAT
1
3
5
9
13
18
23
27
30
PP
RR
DDMM
HHMM
CO2RF
+CO2DF
PARM
MBRF
MBDF
38
LAR
41
FLOW
45
EVAP
49
GSGS
53
TLF
56
+PNN
60
CINT
The character string terminates with a SPACE AND TERMINATES WITH <CR>.
It is only shown above on 2 lines for convenience.
The position of each character in the string is numbered to facilitate string handling in any
user program.
See previous ions for definitions of data.
Subsequent to the transmission of the last record, then <SP> Z <CR> is transmitted.
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Transfer/Logging Software
Transfer/Logging Software
The TPS-2 system is supplied complete with a CD ROM containing a Windows based transfer
and logging software. Instructions and full help menus are provided with the software and
should be referred to as required. Upon receipt of the TPS-2system, load the sofware to your
local computer.
Transfer of Stored Data
To transfer stored data from your TPS-2 main console to your local computer:
1. Using the RS232 data transfer cable, connect the 9 pin plug end directly to the 9 pin
socket on the TPS-2 front panel marked RS232.
2. Connect the other end of the cable to the 9 pin plug on your computers serial port.
3. Power up the TPS-2. With the main menu selected, press key 3 (DMP) and then key
2 (Data Dump). The TPS-2 display will show “CONNECT TO PC ANY KEY TO
SEND”.
4. Next, execute the Transfer Software (Start, Programs, PP Systems, Transfer) on your
computer. For first time users, you will need to set up the software for use with your
TPS-2. Under Preferences, go to “Instrument Type” and set it to TPS and also
check/set the proper COM Port on your computer that is being used to transfer the
software. After this is completed, these settings will be saved and you will no longer
have to step through this operation again.
5. As instructed on the screen, click on the Transfer button on the lower left hand
corner of your computer screen.
6. You will then be asked to name the data file (.dat extension assumed). Enter a name
here and click the Save button.
7. On the TPS-2 main console, press any key to transfer the stored data. Upon
completion of transfer, the message
Once the data is on your computer, you can now import it into your favorite spreadsheet
program for further analysis.
Logging Data
To log data from your TPS-2 using a computer:
1. Using the RS232 data transfer cable, connect the 9 pin plug end directly to the 9 pin
socket on the TPS-2 front panel marked RS232.
2. Connect the other end of the cable to the 9 pin plug on your computers serial port.
3. Power up the TPS-2. With the main menu selected, press key 3 (DMP) and then key
2 (Data Dump). The TPS-2 display will show “CONNECT TO PC ANY KEY TO
SEND”.
4. Next, execute the Transfer Software (Start, Programs, PP Systems, Transfer) on your
computer. For first time users, you will need to set up the software for use with your
TPS-2. Under Preferences, go to “Instrument Type” and set it to TPS and also
check/set the proper COM Port on your computer that is being used to transfer the
software. After this is completed, these settings will be saved and you will no longer
have to step through this operation again.
5. As instructed on the screen, click on the Log button on the lower left hand corner of
your computer screen.
6. You will then be presented with logging options which can be set up according to your
requirements. You have the following options:
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Transfer/Logging Software
Auto Logging
Manual Logging
Capture All Records
View Only
To automatically record measurements (per
settings under File, Preferences)
To manually record measurements (using the
record key (0/R)
To log all records.
To view TPS-2 data on your computer screen
7. After making your selection, you will be asked to name the data file (.dat extension
assumed). Enter a name here and click the Save button.
You can log up to 4 different variables at a time:
CO2 Ref.
CO2 Diff
H2O Ref
Mb Diff
PAR
Air T
Flow
Evap
Leaf T
PN
Ci
Reference CO2 concentration (ppm)
Differential CO2 concentration (ppm)
Reference H2O concentration (mb)
Differential H2O concentration (mb)
PAR -Photosynthetically Active Radiation (µmol m-2 s-1)
Air Temperature (oC)
Flow rate (ml/min)
Evaporation/transpiration rate (mmol m-2 s-1)
Leaf temperature (oC)
Photosynthesis rate (µmol m-2 s-1)
Inter Cellular CO2 concentration (ppm)
Simply tick off the variables that you would like displayed. The button in the upper right hand
corner of the display shows you which measurement screen is displayed. Click on this button
to toggle from one variable to the other.
Once the data is on your computer, you can now import it into your favorite spreadsheet
program for further analysis.
For more information on transferring/logging data, graphing preferences and system setup,
refer to the help menus.
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Maintenance
Maintenance
Air Sampling Pump
The TPS-2 air sampling pump is a “rotary vane” style pump. Rotary vane pump components
wear with prolonged use and material from the vanes may build up within the pumps. This
can eventually reduce the pumping efficiency or even cause them to seize. The normal signs
of a bad pump are as follows:
1. Noise. A worn pump usually sounds rough or vibrates.
2. Temperature. The outer casing is hot when touched with your fingers.
Air Sampling Pump Replacement
It is very easy to replace a bad air sampling pump. First, trace the electrical connection to the
pump and disconnect the 2-pin connector from the terminal on the TPS-2 circuit board.
Secondly, the electrical connector is removed by gently bending back the connector lock and
sliding out the connector. Please note the orientation of the red and black wire for
correct re-fitting of the pump. The pump itself is secured in position by the gas tubing
connections. Finally, remove the tubing from the inlet and outlet ports on the pump and lift
out.
Fit the new pump making sure that:
1. The flat back part of the pump sits flush on its manifold.
2. Connect the inlet tubing to the inlet port and the outlet tubing to the outlet port on the
pump.
3. Finally, the 2-pin electrical connector should be reconnected in the same orientation.
The two notches on the connector latch with the corresponding lock.
Cleaning The Air Sampling Pump
During prolonged operation, the vanes inside the pump will wear and deposit material inside
the pump. It is sensible to clean the pump by periodically flushing it with with isopropyl
alcohol. The following procedure can be adopted:
1.
Connect the pump to a 6-12V source and fit a 30mm tube to the pump inlet.
(i.e. the TPS-2 can be used to supply power via the pump electrical connector. It is,
however, essential that the flushing is performed outside of the instrument to avoid
spillage into it).
2.
Hold the pump above a beaker of isopropyl alcohol and dip the tube into the alcohol (See
below). Run the pump to draw alcohol through it. A small roll of cotton wool in the inlet
pipe can act as a filter for the re-circulating alcohol.
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Maintenance
Pump
Electrical
Connector
Alcohol
If the pump is seized, it may be freed by tapping it on the bench or by reversing the
voltage to run it backwards.
3.
Run alcohol through the pump for a minute or two to ensure that any material is removed.
When finished, run the pump in air for at least 15 minutes to allow any residual alcohol to
evaporate. Ideally, let the pumps dry outside of the TPS-2 overnight. If the pumps are
reconnected prematurely, the absorber chemical (soda lime) will be exhausted quicker
than usual.
Air Inlet Filters
All the air inlets are protected by hydrophobic filters. Periodically check them and replace if
dirty.
12V Lead Acid Battery
The 12V 7.0 Ah sealed, rechargeable, lead acid battery should last for several years as long
as it is properly maintained. Based on manufacturer’s data, the battery is non-spillable
(qualified to non-spillable UN2800 standards) and can be used in any orientation. It has a
float design life of 5 years. It should be checked periodically to ensure that it takes up charge.
Measuring the voltage across the terminals of the battery after it has been charged overnight
can assess this.
Please Note. The internal 12V battery should always be fully charged before long-term
storage. If it is stored in a low or discharged state, it is possible that it will become deepdischarged. If this occurs, the charge capacity of the battery is permanently reduced and will
require replacement.
EPROM
The firmware and factory measured calibration factors for the TPS-2 are stored on a memory
chip commonly referred to as an EPROM inside the instrument. This should never require
maintenance but it may need to be replaced if the system is upgraded or new firmware is
released.
The EPROM that is used in the TPS-2 must be protected from static electricity. As a result,
there are several precautions that the customer should take before removing EPROMS. The
risk of damage can be minimized by earthing both the operator and the lab bench surface.
This can be done by covering the surface of the bench with a conductive material (e.g.
TPS-2 Portable Photosynthesis System Operator's Manual – Version 2.01
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Maintenance
aluminium foil) that is electrically connected to an earthing point such as a metal water pipe or
tap. The operator should also be earthed using a wrist strap or by holding a wire that is
connected to the same earthed point. Please contact PP Systems for further information.
Once suitable earthing arrangements have been made, the TPS-2 enclosure can be opened
to gain access to the circuit board containing the EPROM. The position of the EPROM is
shown above.
Each EPROM is located in a specific orientation. Before starting to remove the chip, note the
position of the notch on the end of the chip relative to the rest of the instrument. Using a
small, flat screwdriver, gently pry the EPROM up until it is removed from its socket. When
fitting the new EPROM to the socket, be careful not to bend any pins. Place the EPROM in
the socket (noting the notch on one end of the EPROM) and gently press down to secure in
place.
Very Important. After replacing the EPROM, you should reinitialize the instrument before
use (see 2: INITIALISE on page 34).
Absorber Columns & Desiccants
The condition of the chemicals within the absorber columns must be regularly checked, and
replaced as necessary. To remove any of the columns, first lay TPS-2 on its back so that you
are looking down on the columns, rather than the screen as in normal use. Hold both ends of
the column firmly, and pull upwards. Do not lever out one end only, as this will damage
the end fitting. The end fitting(s) can then be removed and the contents tipped out.
Columns are fitted with foam disks at each end to stop the contents spilling out if the ends are
inadvertently pulled off during removal. When replacing the contents, the columns should be
tapped to ensure tight packing, and the foam replaced as found. The "O" rings on the end
fittings should be occasionally lightly smeared with silicone grease to aid ease of fitting.
Take care when replacing the end fittings as the "O" rings can roll up and out of the groove.
This will give rise to leaks and the TPS-2 will not work properly.
There can be a very tight fit between the tubes and end fittings. Pushing the end fittings on
without proper care can cause the tubes to crack. Again this will allow air to leak in and out of
the column.
For the latest information on soda lime and envirogel
desiccants including Material Safety Data Sheets (MSDS),
please visit our website.
TPS-2 Portable Photosynthesis System Operator's Manual – Version 2.01
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Maintenance
Soda Lime Specification
Chemical Composition
Physico-Chemical Data
Hazardous
Decomposition
Protective Measures,
Storage & Handling
Measures In Case Of
Accidents & Fires
Components:
Calcium Hydroxide:
Sodium Hydroxide:
Water:
Indicator (Inorganic Salt):
Form:
Colour:
Odour:
Bulk Density:
Solubility in Water
pH in Water
Incompatible Substances
Products
Storage Conditions
Preferred temperature range
Clean dry environment.
0 – 35oC
Store away from direct
heat/sun.
Protective Measures
Avoid inhaling dust.
Wash hands after handling.
Industrial Hygiene
Keep containers closed.
Keep contents dry.
Contain material.
Sweep or vacuum up.
Transfer solids to metal or
plastic container for
disposal.
Wash down spillage with
water.
Spillage
Suit. Extinguishing Media
First Aid
Hazard Labelling
% W/W
(Ca(OH)2) > 75.5%
(NaOH) < 3.5%
< 21.0%
< 0.2%
Granules
Green (Exhausted : Brown)
None
0.9 g/cm3
None
12-14
Acids, Chloroform,
Trichlorethylene.
None
Inhalation
Water, CO2, Powder,
Foam, Halon.
Remove from exposure.
Obtain medical attention if
discomfort persists.
Skin Contact
Drench with clean water.
Obtain medical attention if
skin becomes inflamed.
Eye Contact
Irrigate thoroughly with
clean water.
Obtain medical attention.
Ingestion
Wash out mouth
thoroughly.
Drink water.
Obtain medical attention.
Transport Codes
Hazard Classification
None required.
None.
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Maintenance
Envirogel Specification
1.
2.
Product Identification
Name
Envirogel
Company
Address
Brownell Ltd
Unit 2, Abbey Road Industrial Park
Commercial Way
Park Royal, London NW10 7XF
Telephone number
Fax number
Emergency phone
+44 (0)20 8965 9281
+44 (0)20 8965 3239
+44 (0)20 8838 8408
Composition/Information on the components
Chemical Description
Formula
CAS (R Phrase Classification)
3.
Orange to Green Indicating Silica Gel
SiO2
112926-00-8 amorphous silica 98.2%, activated
colouring agent 0.2% max.
Health Hazard Identification
Do not breathe dust or exceed the exposure limits
4.
First Aid Measures
Inhalation
Skin Contact
Eyes Contact
Ingestion
5.
Fire Fighting Measures
Extinguishing Media
6.
Remove from source of exposure.
Wash spillage from skin with soap and water
Wash immediately with copious amounts of water
and obtain medical attention.
Wash out mouth with water. If large amount
swallowed or symptoms develop
Not applicable. Inorganic compound. Not
combustible.
Accidental Release Measures
Personnel Precautions
Do not inhale. Wear appropriate protective
clothing. Dust mask essential if conditions are
dusty See section 8 for exposure limits
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Maintenance
Spillages
7.
8.
Contain spillage. Collect in suitable containers for
recovery or disposal.
During collection avoid creating dust.
Handling and Storage
Handling
Avoid creating any dust. Do not smoke. During
handling electrostatic charges can accumulate
(see BS 5958 for advice on the control of static.)
Storage
All containers must be closed air tight and kept in
a dry place
Exposure Control / Personal Protection
Occupational Exposure Standards:
Synthetic amorphous silica
Engineering Control Measures
Respiratory Protection
Hand Protection
Eyes Protection
Protection During Application
9.
Silica amorphous, total inhalable dust: UK EH40:
OES 6mg/m3 8h TWA.
Silica amorphous, respirable dust: UK EH40: OES
2.4mg/m3 8h TWA.
Silica Gel: ACGIH: TLV 10mg/m3 8h TWA.
Activation agent: ACGIH: 0.5mg/m3 8h TWA.
Engineering methods to prevent or control
exposure are preferred. Methods include process
or personnel enclosure, mechanical ventilation
(dilution and ocal exhaust), and control of process
conditions.
Avoid inhalation of dust. Wear suitable respiratory
protective equipment if working in confined spaces
with inadequate ventilation or whenever there is
any risk of the exposure limits being exceeded.
Wear protective gloves.
Wear suitable eye protection.
Handle in well ventilated conditions in accordance
with good industrial hygiene and safety practices.
Physical and Chemical Properties
Aspect
Colour
Odour
pH
Melting Point (oC)
Boiling Point
Flash Point
Explosion Limits
Bulk Density
Solubility in Water
Thermal Decomposition
Beads
Dry: yellow/orange Saturated: Green
Odourless
2-10 at 5% w/w in water
>1000
Not Applicable
Not Applicable
Not Applicable
720kg per cu meter (typical)
less 1.0% in weight
Stable except when saturated water released
during regeneration
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Maintenance
10.
Stability and Reactivity
Stability
Conditions to Avoid
Materials to Avoid
Hazardous Decomposition
11.
Toxicological Information
Toxicity
Eye Contact
The lethal dose for humans for synthetic
amorphous silica is estimated at over
15,000mg/kg.
Synthetic amorphous silica gel has little adverse
effect on lungs and does not produce significant
disease or toxic effect when exposure is kept
below the permitted limits. However existing
medical conditions (eg asthma, bronchitis) may be
aggravated by exposure to dust. Effects of dust
may be greater, and occur at lower levels of
exposure in smokers compared to non-smokers.
Dust may cause discomfort and mild irritation.
Skin Contact
Dust may have a drying effect on the skin.
Carcinogenicity
Amorphous silica is not classifiable as to its
carcinogenicity to humans (Group 3).
Health Effects Inhalation
12.
Ecological Information
Ecotoxicity
13.
Product can be reactivated in an oven for re-use.
This material is not classified as hazardous waste
under EEC Directive 91/689/EEC.
Dispose of in accordance with all applicable local
and national regulations.
This material is not classified as special waste
under UK Special Waste Regulations 1996 and
can be disposed of by landfill at an approved site.
Transport Information
UN Class
15.
Synthetic amorphous silica is virtually inert and
has no known adverse effect on the environment.
Disposal
Product Disposal
14.
Hygroscopic
High temperatures in excess of 155oC
None known
Hygroscopic material
Not classified as dangerous goods under the
United Nations Transport Recommendations.
Information on Regulation
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Error and Warning Displays
EC Classification
S phrases
This product is not classified as dangerous.
Handle in accordance with good industrial hygiene
and safety practices.
Avoid inhalation of dust.
EINECS Listing
TSCA Listing
AICS Listing
DSL/NDSL (Canadian) Listing
Preparation – all components listed
Mixture – all components listed
Mixture – all components listed
Mixture – all components listed
Error and Warning Displays
The Error and Warning displays are listed in alphabetical order.
BATTERY VOLTS∗10
= XXX
Indication
Battery voltage < 10.5v
Remedy
Re-charge battery. If it then immediately re-occurs check the battery charger voltage.
CALCULATION NOT
COMPLETED
Indication
Record key pressed too rapidly after previous recording and the measurements have not
been updated.
Remedy
Wait a few seconds until previous measurement is updated before making next recording.
CHECKSUM MEMORY
ERROR SEE MANUAL
Indication
Should not be experienced by most users. Memory corruption is generally caused by failure
to turn off TPS-2 when changing an EPROM. Also could be caused by a miss read of an
EPROM due to a glitch on data/address lines.
Remedy
Initialise, recalibrate and clear the memory.
If it regularly re-occurs then contact you agent.
DATABASE FULL
PRINT AND RESET
Indication
820 records have been taken. Further records overwrite last record.
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Error and Warning Displays
Remedy
Dump data and then clear memory.
ERROR CODE NN
Indication
Calculation error. Should rarely be seen as most errors have been trapped. Please report
circumstances of its display and the error code (NN) to PP SYSTEMS.
Remedy
Press any key to return to the main menu.
Reset all set-up values in record menus.
MEMORY CORRUPT
PLEASE RESET
Indication
TPS-2 has 2 pointers to its record store. One is to the number of records currently stored, the
other is the address of the next free record. The pointers can get out of line if TPS-2 is
switched off in the middle of recording. Therefore, always return to a menu before switching
off.
Another possible cause is that the battery that maintains the memory power when TPS-2 is
switched off has failed.
On start up, TPS-2 checks that the pointers agree. If they do not, then this message is
displayed.
Remedy
Clear the memory. If after switching off the message is repeated then contact your agent.
NO MORE RECORDS
IN STORE
When transferring stored records from TPS-2 to a PC, this is displayed when all the records
have been sent.
In order to ensure high quality, accuracy and continued success of your TPS-2 system, it is
recommended that your system be returned annually to the factory (or authorised agent) for
our APM service. An APM includes inspection of all internal plumbing, replacement of all "O"
rings, filters and chemicals, and an electrical check and full calibration of the instrument. The
Leaf Cuvette gaskets and piping are replaced, and all sensors are checked and calibrated.
The entire system is thoroughly serviced and calibrated by factory trained service engineers.
Please consult with PP Systems or your local agent for more details regarding this service.
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TPS-2 Photosynthesis Calculations
TPS-2 Photosynthesis Calculations
STEP 1
Calculate the mass flow of air per unit leaf area entering the cuvette (W).
The TPS-2 mass flowmeter is calibrated to read the volume flow at 20o C & 1 bar (V20).
Since the molar volume is 22.41 at 0o C and 1 standard atmosphere, then:W = (V20 / 1,000) x (1 / 22.41) x (273 / 293) x (1 / 1.013) x (10,000 / a)
where a is the projected leaf area.
STEP 2
The Transpiration rate (E) is now calculated from the water vapour pressure of the air
entering (ein) and leaving the cuvette (eout).
The molar flow of water into the cuvette is:(ein / P) x W mol m-2 s-1
The molar flow of air out of the cuvette, due to the addition of the transpired water, is (E+W).
Therefore, the molar flow of water out of the cuvette is:(eout / P) x (E + W) mol m-2 s-1
But the difference between the molar flows into and out of the cuvette must equal the
transpiration, thus:E = [(W + E) x (eout / P)] - (W x ein / P)
Therefore:E = [W x (eout - ein)] / (P - eout)
STEP 3
The leaf temperature (tleaf) is now calculated from the energy balance. It can be shown
(Reference 1) that the difference between air and leaf temperature is as follows:∆ t = (H -
E) / (0.93 x Ma x Cp /rb + [4ó x (tc + 273)3)]
tleaf = tc + ∆ t
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TPS-2 Photosynthesis Calculations
Where:H
= the incident radiation absorbed by the leaf.
= the latent heat of vaporisation of water.
E
= the transpiration rate.
Ma
= the molecular weight of air.
Cp
= the specific heat at constant pressure.
rb
= the boundary layer resistance to water vapour transfer (0.93 converts it to
that for heat).
ó
= Stefan Boltzmann's constant.
tc
= the cuvette air temperature.
H is calculated from the Photon flux incident on the cuvette (Q), taking into account the ratio
of infrared to PAR in the light source, the transmission through the windows, and
reflection/absorption by the leaf.
In the program, the following approximation is made:4ó x (tc + 273)3 - > > 4.639 + (0.0583 x tc)
STEP 4
From the leaf temperature, we can derive the saturated vapour pressure at leaf temperature
(eleaf) and the stomatal resistance (rs).
From step 2:E = W x (eout - ein) / (P - eout)
but also:E = (eleaf - eout) / [P x (rs + rb)]
therefore:rs = [[(eleaf - eout) / (eout - ein) x (P - eout) / P] / W] - rb
but:(P - eout) / [(eout - ein) x W] = 1 / E
therefore:rs = [(eleaf - eout) / (E x P)] - rb
and:gs = 1 / r s
STEP 5
The photosynthesis rate (A) is calculated from the difference in the CO2 concentration
entering (Cin), that leaving (Cout), and the flow rate through the cuvette. The CO2 readings
are assumed to be corrected for water vapour, temperature, and atmospheric pressure. Also,
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TPS-2 Photosynthesis Calculations
the addition of water vapour by transpiration in the leaf cuvette dilutes the outgoing air, and
this must be compensated for in the calculation:A = Cin x W - Cout x (W + E)
= - [W x (Cout - Cin) + Cout x E)]
But, (Cout - Cin) is the CO2 difference that is calculated and displayed by CIRAS.
STEP 6
Finally, for the calculation of the sub-stomatal cavity CO2 concentration (Cleaf), we use the
equation derived by von Caemmerer & Farquhar (Reference 3):Cleaf = [[(gc - E / 2) x Cout] - A] / (gc + E / 2)
where:gc = 1 / (1.6rs + 1.37rb)
Please Note: These calculations assume that the leaf is exposed on both surfaces, that the
upper and lower boundary layer resistances are similar, and that the stomata are evenly
distributed on both surfaces.
Symbol Definitions
Measured Parameters
Symbol
Measured Parameters
Units
V
Volume flow rate of dry air into cuvette
cm3 s-1
a
Projected leaf area
cm2
rb
Boundary layer resistance to water vapour
m2 s mol-1
P
Atmospheric pressure
bar
V20
Mass flow of air into cuvette at 20o C and 1 bar
cm3 s-1
Q
Photon flux density incident on cuvette
µmol m-2 s-1
tc
Cuvette air temperature
oC
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TPS-2 Photosynthesis Calculations
Calculated Parameters
Symbol
Calculated Parameters
Units
W
Mass flow of dry air per unit leaf area
mol m-2 s-1
ein
Vapour pressure of water, of air into cuvette
bar
eout
Vapour pressure of water, of cuvette air
bar
es
Saturated vapour pressure, at cuvette air temperature
bar
eleaf
Saturated vapour pressure, at leaf temperature
bar
tleaf
Leaf Temperature
oC
H
Radiation absorbed by the leaf
W m-2
∆t
Temperature difference between leaf and air
oC
Cin
CO2 concentration of air into cuvette
µmol mol-1 *
Cout
CO2 concentration of cuvette air
µmol mol-1 *
Cleaf
Sub-stomatal cavity CO2 concentration
µmol mol-1
rs
Stomatal resistance to water vapour
m2 s mol-1
gs
Stomatal conductance to water vapour
mmol m-2 s-1
gc
Total conductance to CO2 transfer
mmol m-2 s-1
A
Rate of CO2 exchange in the cuvette
(Photosynthesis Rate)
µmol m-2 s-1
E
Transpiration Rate
mmol m-2 s-1
* These are assumed to be corrected for water vapour effects on the analyzer measurement,
analyzer temperature, and atmospheric pressure.
Physical Constants Used In Equations
Volume of one Kg mole of gas =0.0224 m3, at 1013 millibars pressure and 273 K.
Latent heat of vaporisation of water (
) = 45064.3 - (tc x 42.9)
Molecular weight of air (Ma) = 28.97
Specific heat at constant pressure (Cp) = 1.012 J g-1 K-1
Stefan Boltzmann constant (ó) = 5.7 x 10-8 W m-2 K-4
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TPS-2 Photosynthesis Calculations
Derivation of Saturated Vapour Pressure of Water (bar) from Air Temperature
From:New Equations For Computing Vapour Pressure. A.L. Buck, J. Appl. Meteorol., Vol. 20,
1527-1532, 1981.
Above 0o C:es = 6.13753 x EXP [ta (18.564 - ta / 254.4) / (ta + 255.57)] x 10-3
Below 0o C (above water NOT ice):es = 6.13753 x EXP [17.966 x ta / (ta + 247.15)] x 10-3
Technical References
Parkinson, K.J. (1983). Porometry in S.E.B. Symposium of Instrumentation for Environmental
Physiology. Cambridge University Press.
Parkinson, K.J., W. Day and J.E. Leach (1980). A Portable System for Measuring the
Photosynthesis and Transpiration of Graminaceous Leaves. J. EXPT. BOT., Vol. 31., pp
1441-1453.
von Caemmerer, S. and G.D. Farquhar (1981). Some relationships between the biochemistry
of photosynthesis and the gas exchange of leaves. PLANTA, Vol. 153., pp 376-387.
Corrections to Stomatal Resistance Measurements For Differing Transpiration Rates
Under Upper and Lower Leaf Surfaces
It is necessary to assume that the internal diffusion resistance to water vapour and CO2 are
small compared with the stomatal resistances, so that there are uniform H2O and CO2
concentrations within the leaf.
ea
2RB = RBu
RSu
RSu
RBu
el
Leaf
el
CInt
RSl
ea
==
RSl
2RB = RBl
ea
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RBl
TPS-2 Photosynthesis Calculations
Where:(ea) and (el) are the water vapour pressures of the cuvette air and the leaf air spaces
respectively
RB is the boundary layer resistance for whole leaf, with
RBu = RBl = 2*RB (m2.s.mol-1)
RS is the total leaf resistance
Then for the two leaf surfaces:N and (1-N) are the fractions of the total evaporation
E in mol.m-2.s-1 from the upper(u) and lower(l) leaf surfaces
RSu =
(el − ea ) − 2 * RB
(E * N )
...(1)
and
RSl =
(el − ea )
(E * (1 − N ) )
− 2 * RB
...(2)
For clarity in the following expansion let (el - ea) = D.
Then from 1 and 2:-
(E * N )
1
=
RSu (D − 2 * RB * E * N )
and :-
(E * N )
1
=
RSu (D − 2 * RB * E + 2 * RB * E * N )
Therefore :-
1
1
E * N * (D − 2 * RB * E + 2 * RB * E * N ) + (E − E * N ) * (D − 2 * RB * E * N )
+
=
(D − 2 * RB * E * N ) * (D − 2 * RB * E + 2 * RB * E * N )
RSu RSl
Now :-
RS =
1
1 
 1
+


 RSu RSl 
Therefore :-
RS =
(D − 2 * RB * E * N ) * (D − 2 * RB * E + 2 * RB * E * N )
E * N * (D − 2 * RB * E + 2 * RB * E * N ) + (E − E * N ) * (D − 2 * RB * E * N )
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TPS-2 Photosynthesis Calculations
Which expands to :-
RS =
D * D − 2 * RB * E * D + 4 * RB * RB * E * E * N − 4 * RB * RB * E * E * N * N
E * (D − 4 * RB * E * N + 4 * RB * E * N * N )
...(3)
If we assume that there is equal transpiration on both surfaces
(ie N = 0.5) then :-
RS (eq) =
(D − RB * E )
E
...(4)
Then the error in determination of RS from making the assumption of equal transpiration on
both sides of the leaf is (3) - (4).
After expansion and simplification this becomes :-
N * (1 − N ) − 0 . 25
0 . 25
E * N * (1 − N
−
RB
D
)
…(5)
When N = 0 or 1 then this equals -RB. This follows from the fact that with transpiration on one
side only, the boundary layer resistance to subtract is 2*RB, whereas the original calculation
has subtracted just RB.
Substituting in equation (5) for E/D from equation (4)

ie


1
E
:=
D (RS (eq) + RB ) 
RS (true) = RS (eq) +
N * (1 − N ) − 0.25
N * (1 − N )
0.25
−
RB (RS (eq) + RB )
…(6)
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TPS-2 Photosynthesis Calculations
We can determine the magnitude of the error for various values of RS, RB and N as follows:
0.5
RS = 1
1
0.45
RS = 12
0.4
0.35
1. RB = 0.45 m2s mol-1
2
Error in RS m s mol
-1
2
0.3
2. RB = 0.3 m2s mol-1
0.25
3. RB = 0.15 m2s mol-1
0.2
3
0.15
0.1
0.05
0
0
10
20
30
40
50
60
% Distribution
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TPS-2 Portable Photosynthesis System Operation Manual Revision Log
TPS-2 Portable Photosynthesis System Operation Manual
Revision Log
Revision
Date
Changes
2.01
January 30, 2007
Created for v1.1 firmware to include LED light unit.
TPS-2 Portable Photosynthesis System Operator's Manual – Version 2.01
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User Notes
User Notes
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