Department of Clinical Sciences/ Unit of Tropical Laboratory Medicine
Département des Sciences Cliniques / Unité de Laboratoire de Médecine Tropicale
SOP: Use of min/max thermometers and the registration form for fridges
and freezers
Type: Standard Operating Procedure (SOP)
Status: draft
Written by: vhermans
Reviewed by:
Create Date: 20100106
Save Date: 20100112
1. OBJECTIF
This SOP describes the operation of an electronic minimum / maximum
thermometer of the company VWR and the registration of the temperatures on a
registration form.
2. PRINCIPE
The thermometer is a device used for the daily temperature monitoring of fridges
and freezers. The thermometer uses a separate probe attached to the device by a 3
meter long cable. Every 10 seconds the temperature is measured again. Each day,
the current temperature, the minimum and maximum temperatures need to be
recorded on a registration form that is taped on the fridge/freezer.
3. MATERIALS
-
-
Thermometers min/max -50/+70°C
with fridge sensor (VWR) in plastic
glycerol tube
Registration form
Pen
Tape
Technical specifications of min/max thermometer:
Temperature range:
Temperature inside
Temperature outside
Temperature display resolution
Accuracy
Battery
Unit of Tropical Laboratory Medicine
SOP Thermometers min/max
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-10°C and +50°C
-50°C en +70°C
0,1°C
± 1°C
1,5V, A76
2/22/2010
4. QUALITY CONTROL
Accuracy of this thermometer is ± 1°C. At VWR, the thermometer is calibrated and
tested against thermometer standards traceable to the National Institute of
Standards and Technology (NIST).
At the Institute of Tropical Medicine, the thermometers are calibrated by the quality
service against a reference thermometer. Each thermometer receives a label with a
number (xxx1, xxx2, xxx3, …) and the date it was calibrated (Fig.1). Calibration forms
are kept at the Unit of Tropical Laboratory Medicine and can be consulted at all
time. In the file “Date_name_List Calibration Thermometers” is kept where the
thermometers are located. This file can be found on the K-drive at the Institute of
Tropical Medicine at: K:\UNIT TROPISCHE LABORATORIUM
GENEESKUNDE\LQM\ADMINISTRATION\CALIBRATION. Each thermometer should be
calibrated again every year at the place it is used against a reference thermometer.
Figure 1: Each thermometer receives a label with a
number (xxx1, xxx2, xxx3, …) and the date it was
calibrated.
5. PROCEDURE
1. Register temperature inside fridge/freezer:
1) Press [Room/Fridge] button until “Fridge” is displayed in the right
corner of the screen.
Make sure that “Room” is not displayed in the right
corner when registering the temperature inside the
fridge. When “Room” is displayed you will register the
temperature inside the room.
Figure 2: To register the
temperature inside the
fridge/freezer, press the
[room/fridge] button until “fridge”
is displayed on the screen.
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2) Make sure no “MIN” or “MAX” is displayed in the left corner of the
display (Figure). If “MIN” or “MAX” is displayed in the left corner of
the display, press the [Max/Min] button until the left corner is empty.
Figure 3: Make sure no MIN or
MAX is displayed in the left corner
of the display when registering the
temperature inside the
fridge/freezer.
3) Now, the current temperature inside the fridge/freezer is shown in
the middle of the screen.
4) Write down this value in the indicated column on the registration
form (see chapter 5 on how to complete the registration form).
2. Register maximum measured value inside the fridge/freezer:
1) Press [Max/Min] button until “max” is displayed in the left corner of
the screen.
Figure 4: To register the maximum
temperature inside the fridge/freezer:
Press [Max/Min] button until “MAX” is
displayed in the left corner of the screen.
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2) Press [Room/Fridge] button until “Fridge” is displayed in the right
corner of the screen (Fig.4).
Make sure that “Room” is not displayed in the right
corner when registering the maximum temperature.
3) The maximum measured value inside the fridge/freezer is displayed in
the middle of the screen.
4) Write down the maximum value in the indicated column on the
registration form (see chapter 5 on how to complete the registration
form).
3. Register minimum measured value inside the fridge/freezer:
1) Press [Max/Min] button until “min” is displayed in the left corner of
the screen.
Figure 5: To register the minimum
temperature inside the fridge/freezer:
Press [Max/Min] button until “MIN” is
displayed in the left corner of the screen.
2) Press [Room/Fridge] button until “Fridge” is displayed in the right
corner of the screen (Fig.5).
Make sure that “Room” is not displayed in the right
corner when registering the minimum temperature.
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3) The minimum measured value inside the fridge/freezer is displayed in
the middle of the screen.
4) Write down the minimum value in the indicated column on the
registration form (see chapter 5 on how to complete the registration
form).
4. Reset memory
1) Press and hold [Max/Min] button about 2 seconds to reset memory
to current reading.
2) After about 3 seconds the current temperature appears again on the
display. From then on, the new minimum and maximum
temperatures are recorded in the memory of the thermometer.
Don’t forget to reset the memory! If this is forgotten, the
maximum and minimum temperature of the previous day
will be registered on the registration form.
5. Registration forms
The form consists of 31 cells, one for each day of the month.
1) Make sure the form is clearly visible on the fridge/freezer. If this is
not the case, paste it so that it becomes clearly visible.
2) Check if the header of the registration form is correctly filled in (see
chapter 1)
3) Start to fill in the form at the number that corresponds with the day
of the month.
Ex: Measurements on January the 2nd must be completed in row
N° 2.
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4) Complete all the columns: date, hour, Temperature, Minimum
temperature, Maximum temperature.
5) If there are any remarks or abnormalities, this can be written in the
‘remarks’ column. For example power cuts.
6) Give a completed form (at the end of the month) to the responsible
person of the quality service.
6. Set of Alarm when temperature limits are crossed
Follow the instructions below to program the alarm of the min/max
thermometer to go off when certain temperature limits are crossed.
1) Press and hold the [alarm icon] button for about 2 seconds, the “HIGH
“and “FRIDGE” icons will flash on the display.
Figure 6: Press and hold the [alarm
icon] button for about 2 seconds
2) Press [↑] to set the alarm high limit. Find the red button on the back
of the device.
Holding the [↑] button will advance the value
automatically. The upper limit is +70°C and the
lower limit is -50°C. You can only count upwards;
the value will automatically jump from +70°C to 50°C.
3) Press [alarm icon] button again, the “LOW” and “FRIDGE” icons will
flash on the display.
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4) Press [↑] to set the alarm low limit. Find the red button on the back
of the device.
5) Press [alarm icon] button once more to finish setting
6) If the sensor reading is out of the set limits, the alarm will sound.
7) Press [alarm icon] button to switch off or on.
6. MATERIAL INFORMATION
-
Thermometers min/max -50/+70°C with fridge sensor
You can purchase this thermometers at:
VWR International BVBA
Researchpark Haasrode 2020
Geldenaaksebaan 464
3001 Louvain
Belgique
Email: [email protected]
Tel: + 32 (0)16 385
Article number : 620-0919
Price/piece : € 16,31
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