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Sensor setup
some of the cool air. When the door is shut, the refrigerator cools the interior air back to
4 °C again.
The temperature of the sample is not affected as quickly as the temperature of the air. It
takes time for a volume of water to change temperature. Since it is the sample we wish to
keep at 4 °C and not the air, the sampler thermal sensor accurately simulates the sample
so the controller can maintain the sample temperature exactly. Typical air sensing
thermostats fight to maintain air temperature, not sample temperature and so are not as
accurate or efficient at preserving samples.
6.5.1 Thermal sensor programming
1.
From the Main Menu, select
OPTIONS, ADVANCED OPTIONS, CALIBRATION,
THERMAL SETUP.
2.
Enter the refrigeration compartment temperature in degrees centigrade from 2–10 °C.
Typical sample preservation temperature is 4 °C.
6.5.2 Thermal sensor calibration
Prerequisites:
•
Ice bath in a 500 mL beaker, using a 50/50 mix of crushed ice and water
•
Lab grade thermometer
Procedure:
1.
Press the
OFF
on the sampler controller to shut off the sampler controller.
2.
Remove the pull out tray.
3.
Remove the Reference Temperature Sensor (RTS) from the bracket. Place the
beaker/ice bath next to the bracket.
4.
Place the sensor and the lab grade thermometer in the
beaker / ice bath.
5.
With the sampler controller off and the door closed, wait approximately 30 minutes for
the reference sensor and lab thermometer to stabilize with the ice bath temperature.
6.
After waiting 30 minutes, mix (swirl) the ice bath.
7.
Press the controller
ON
button.
8.
Go to
MAIN MENU, OPTIONS, ADVANCED OPTIONS, CALIBRATION
. Press
SELECT
.
9.
Highlight
THERMAL SETUP
and press
SELECT
.
10. Highlight
THERMAL CALIBRATE
and press
SELECT
.
11. The screen displays the current temperature read by the controller. In degrees C,
enter the reading indicated on the thermometer in the ice bath, to the nearest one
tenth degree, next to the actual temperature display and press
ACCEPT
. This
completes the calibration procedure.
12. Install the RTS.
Goodnal STP ST041 Pre Treatment (Sigma 900 MAX All Weather Refrigerated Sampler) Vendor Manual
Q-Pulse Id VM373
Active 29/10/2013
Page 78 of 122
