Techne RS232 - Manual (Page 24)

D B - 2 D w i t h R S 2 3 2 O P E R A T O R ’ S M A N U A L
P A G E 22
Calibration
Remember that if you change the calibration from that set at the factory
you may change the calibration at all temperatures. You may get different
calibration with different blocks.
Make sure that you have good thermal contact between the blocks and the heater
platen in the Dri-Block. In order to ensure that the calibration you are setting
is correct, you will need to use an independent calibrated probe or thermometer.
Measure the actual temperature of the particular block you want to use in the
Dri-Block using the calibrated probe or thermometer. If the calibration is not
correct then you can follow this procedure. Make sure that the block and the
unit are below 35°C.
a Set the temperature display to 0.0°C. This will ensure that the block is at
ambient temperature for the next procedure.
b Hold down the Up and Down buttons and then press the Set button at the
same time for 5 seconds The display will change from the set temperature,
0.0, to the block temperature to indicate the start of self-calibration.
c After a period of 17 minutes the display will change from the block
temperature (eg 40.0°C) to “EEEE”. Measure the actual temperature of the
block using the thermometer or probe. Press the ‘SET’ button and either the
‘UP’ or the ‘DOWN’ button to adjust the display to the same temperature
as the measured value.
d Press the ’UP’ and ‘DOWN’ buttons together to confirm the value. The
display will return to the block temperature and the heater will come full on.
e After a period of 29.75 minutes the display will change from the block
temperature (eg 95.0°C) to “EEEE”.
f Measure the actual temperature of the block using the thermometer. Press
the ‘SET’ button and either the ‘UP’ or ‘DOWN’ button to adjust the display
to the same temperature as the measured value.
g Press the ‘UP’ and the ‘DOWN’ buttons together to confirm the value. The
display will return to the block temperature and the unit will control with the
new calibration parameters.
h Set the temperature to the particular temperature you require. Measure the
temperature when the block temperature has stabilised. Repeat the procedure
as necessary; you may need to put in an off-set.