Electronic
Pressure Measurement
Air Flow Transmitter
Type A2G-25
WIKA Datasheet A2G-25
Applications
■■ Measuring the volume flow in ventilation ducts for air and
non-combustible gases
■■ Used for fans and ventilators of various manufacturers
■■ Monitoring of air volume flow or pressure directly
on the air handling unit
■■ For use with fans/blowers from various manufacturers
Special Features
„„ Easy installation
„„ User-friendly display
„„ Easy-to-read LCD display
„„ Temperature compensated
■■ Output signals for differential pressure and air volume flow
■■ Air flow calculation based on k factor
Air Flow Transmitter model A2G-25
Description
Version
In accordance with the CE requirements of EMC Directive
89/336/EEC, ROHS Directive 2002/95/EY
Accuracy
At 4 InWC and 8 InWC ± 0.02 InWC: ±1.5 % of display
At 20 InWC and 28 InWC : ±0.03 InWC: ±1.5 % of display
Display ranges
0 ... 4 InWC, 0 ... 8 InWC, 0 ... 20 InWC or 0 ... 28 InWC
Selectable units on the display: LPM, m3/s, m3/h, cfm, l/s, scfh,
mbar, mmWC, kPa or Pa
Long-term stability
At 4 InWC and 8 InWC: ±0.03 InWC
At 20 InWC and 28 InWC: ±0.1 InWC
Manual zero adjustment (standard)
Automatic zero adjustment (optional): ±0.03 InWC
WIKA Datasheet A2G-25 · 3/2013
Maximum working pressure
100 InWC
Operating temperature
Ambient: -4...+160°F
Medium: 23 … +122 °F
Permissible ambient humidity
0 ... 95 % rH, non-condensing
Ingress protection
NEMA 3 (IP54 per EN 60529 / IEC 529)
Weight
5.2 ounces (150 grams )
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Standard features
Process connection
Hose barb (ABS)
Measuring element
Piezo sensor
Display
Alphanumeric display with menu-driven user interface
Case
Plastic (ABS)
Electrical connection
M16 PG-Gland
Output signal
V OUT DC 0 … 10 V, Load R minimum 1 kΩ linear to
adjusted output unit,
P OUT DC 0 … 10 V, Load R minimum 1 kΩ linear to
adjusted output unit
Supply voltage
AC 24 V or DC 24 V ±10 %
Zero point adjustment
On the display keyboard
Standard accessories
„„ 2 mounting screWC
„„ 2 plastic duct connectors
„„ 3 feet PVC hose, inner diameter 1/8” / 3/16”
Options
■■ Automatic zero adjustment
(Long-term stability ±1 Pa)
Wiring diagram
V-scale output can be changed (in relation
to the selected output unit)
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WIKA Datasheet A2G-25 · 3/2013
40376281X.01
Connection diagram
Zero point adjustment
Manual zero adjustment (standard)
1. Both the + and the – flow inputs must be disconnected.
2. Press the zero point button until the red LED lights up.
3. Wait until the LED switches off again. Now the instrument
can be reconnected.
4. In normal operation, we recommend that a zero adjustment
is carried out every 12 months.
ZERO
Automatic zero adjustment (option)
The automatic zero adjustment adjusts the zero point
from time to time so that a manual zero adjustment is not
necessary. During the zero adjustment (3 seconds every
10 minutes), the output signal and the display show the last
measured value.
Dimensions in inches
1.69
2.05
2.76
0.15
3.36
40376281.01
2.65
0.47
0.39
0.59
WIKA Datasheet A2G-25 · 3/2013
0.75
0.91
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Menu selections and initialization instructions for installation
If buttons are not pressed within 20 seconds the device returns to the normal measuring mode.
1. Press the Select button for at least 2 seconds to enter the menu.
2. Select the fan manufacturer.
3. Each fan manufacturer has its own specific K-value.
Please take the correct K-value from the data sheet:
Fläkt Woods
(k = 0,3 … 99)
Rosenberg
(k = 37 … 800)
Nicotra (c = 10 … 1500)
Comefri (k = 10 … 2000)
Ziehl
(k = 10 … 1500)
Ebm-Papst
(k = 10 … 1500)
Gebhard (k = 50 … 4700)
4. The following units will be displayed:
m3/s, m3/h, cfm, l/s, scfh, lpm, kPa, mbar, mmWC, inchWC or Pa.
5. Pressure output unit (and P OUT scale)
At 1,000 Pa
0 ... 1,000 Pa
0 ... 1 kPa
0 ... 10 mbar
0 ... 100 mmWC
0 ... 4 inchWC
At 2,000 Pa
0 ... 2000 Pa
0 ... 2 kPa
0 ... 20 mbar
0 ... 200 mmWC
0 ... 8 inchWC
At 5,000 Pa
0 ... 5000 Pa
0 ... 5 kPa
0 ... 50 mbar
0 ... 500 mmWC
0 ... 20 inchWC
The maximum value corresponds to an output signal of 10 V
6. At 7,000 Pa
0 ... 7,000 Pa
0 ... 7 kPa
0 ... 70 mbar
0 ... 700 mmWC
0 ... 28 inchWC
Flow output unit for defining the V OUT scale
7. V OUT scale, selectable:
m3/s
→ 10 V = 1 … 50 m3/s
m3/h
→ 10 V = 4000 … 200000 m3/h
cfm
→ 10 V = 2000 … 100000 cfm
l/s
→ 10 V = 1000 … 50000 l/s
scfh
→ 10 V = 1000000 …6000000 scfh
lpm
→ 10 V = 60000 … 3000000 lpm
8. Stepless response time selection.
9. Press the END button and the instrument returns to the normal
measuring mode.
The specifications given in this document represent the state of engineering at the time of publishing.
We reserve the right to make modifications to the specifications and materials.
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© Copyright 2013 WIKA Instrument, LP. All Rights Reserved.
WIKA Datasheet A2G-25 · 3/2013
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WIKA Instrument, LP
1000 Wiegand Boulevard
Lawrenceville, GA 30043-5868
Tel: 888-WIKA-USA • 770-513-8200
Fax:770-338-5118
E-Mail:[email protected]
www.wika.com