RADIOMETER TCM3 - Page 26

2. TCM3
TCM3 and TCM30 Service Manual
Checkout and Adjustment, Continued
Step 0:14 If the readings in step 0:14 are not within the stated ranges, repeat the adjustments
(continued) in step 0:12 and repeat the checks in step 0:14.
If the readings in step 0:14 are still outside the range, the Analog PCB is defective
and must be replaced.
Temperature This procedure checks the zero-point and gain for the temperature channel 2.
The procedures require the cabinet to be opened.
Action
Channel 2
Step
Step 0:13 1.
2.
3.
Set the simulator THERMISTOR switch to DOUBLE.
Set the simulator TEMPERATURE switch to 45 °C.
Check that the display shows 44 965 and 45 035 (zero-point).
If outside, adjust R26 on the Analog PCB to a reading between 44
995 and 45 005.
Set the simulator TEMPERATURE switch to 37 °C.
Check that the display reading is between 36 965 and 37 035 (gain).
If outside, replace the Analog PCB.
Heat Regulator This procedure checks the regulator for heating the electrode.
Step Action
Step 0:15 1. Set the simulator THERMISTOR switch to DOUBLE and the
TEMPERATURE 37 °C.
2. Connect the DVM+ to simulator HEAT- and DVM- to HEAT+ and
check that the voltage is between —11.8 and —14.2 V (electrode
voltage, max. heat).
3. Move the DVM+ to simulator GND and check that the voltage is
1.00 V +/- 0.05 V (electrode current, max. heat).
4. Set the simulator TEMPERATURE to 45 °C and check that the
voltage is less than 0.05 V (electrode current, min. heat).
5. Set the simulator TEMPERATURE to 46 °C and check that the
voltage is less than 50 mV (max. temp.).
If the DVM readings in step 0:15 are not within the stated tolerances, check the
heat supply circuit on the Main and Analog PCBs, and replace the defective PCB.
Continued on next page
Innano +