Physitemp Instruments CT-3 - Manual (Page 3)

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thermometer under test, continue the calibration check. If they do not, the thermocouple
thermometer may require recalibration.
Note: ensure that the mercury thermometer is viewed perpendicular to the tip of the
mercury column to avoid parallax effects.
3.4
Press the grey ON ADJUST button on the CT-3. While holding down this button, turn
the ADJUST knob until the thermocouple thermometer displays 25.0 C (77.0  F)
3.5
Continue to hold down the grey button. Press in turn the 0.0 , 15.0 , 37.0 , 45.0 
and 50.0 C buttons. In each case, the thermocouple thermometer should display the
temperature selected to within 0.2 C. If the difference between the thermometer display and
the temperature selected is greater than 0.2 C, the thermocouple thermometer needs to be
recalibrated.
If you are using a Physitemp thermocouple thermometer and do not have calibration facilities,
the instrument can be returned to the factory for calibration.
4.0 BATTERY
REPLACEMENT
4.1
CT-3 uses two EN90 1.5V alkaline cells.
4.2
Place the CT-3 on a flat surface and carefully remove the six screws, which secure the
top cover to the base. Remove the cover carefully. Note the thin wire running between the
thermometer block in the base and the circuit board in the top cover. TAKE EXTREME
CARE WHEN REMOVING THE TOP COVER AND ENSURE THAT THIS WIRE IS NOT
DISLOCATED OR DAMAGED.
4.3
Battery holder is on the underside of the circuit board. Note the orientation of the two
batteries, then remove and replace with new cells of the same type. Press red BATT. CHECK
to verify that the LED lights after new batteries are installed.
4.4
Re-assemble the top cover and base. Be sure that the wire is not caught between them.
Replace washers and screws.