Techne DB-3A - Manual (Page 22)

D B - 3 a n d D B - 3 A O P E R A T O R ’ S M A N U A L
P A G E 20
Setting the Operating Temperature
1. Turn the temperature control knob to the required temperature. Note
that the actual temperature of the block critically depends on the type
of block used and the quality of the thermal contact between the
base of the block and the unit.
2. The heater (and heater indicator) comes on if the set temperature is
higher than the current block temperature.
3. When the set temperature is approached, the heater indicator will
begin to flash and when the temperature is stabilised the indicator
will flash slowly.
4. Due to variations in heat losses with different designs of insert block,
the actual temperature may vary. The units are calibrated using
model F3506 insert blocks.
If you need to control the temperature to a greater accuracy than the
instrument’s set point, place a thermometer in the special hole in one
of the blocks. For greater accuracy still, you can place the thermometer
in the sample liquid in one of the test tubes. In either of these cases,
it may be necessary to readjust the temperature control knob or
preset adjustment to achieve the precise temperature required.
Allow the temperature of the unit to stabilise after each adjustment.
5. There will be a time lag between the heater platten and the insert
block achieving the set temperature due to thermal contact between
them. The insert block may take up to 12 minutes to reach
temperature, as shown in the Specifications on pages 15 and 16.