Ametek Thermox TM2000, Руководство пользователя

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6-10 | Thermox TM2000 Oxygen Analyzer
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If 15 volts is not present, check fuse F1 on the wiring card.
If this fuse is OK, replace the control unit power supply/keypad
module.
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If this fuse is not OK, replace the fuse (1/4 amp, 125 volts, IEC
speed type FF).

Check the interconnecting wiring for short circuits before applying
power to the control unit.
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If you measure 15 volts at terminals 4 (-) and 12 (+) of the sensor
board, then measure across terminals D (+) and 6 (-) on the sensor
board. Twelve millivolts should be measured (this signal is a func-
tion of ambient temperature and may vary up to ± 2 millivolts at
extreme ambient temperature).
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If you don’t measure this voltage, replace the sensor board.
For a furnace temperature set point for a 615°C oxygen cell temperature,
the furnace thermocouple output would be about 27 mVs (take memory
location 88 which is the T/C Ratio calculated during the primary - thermal
calibration and divide the cell temperature by this value to come up with
the furnace temperature set point).
Note: The cell thermocouple compensation circuit on the 80471SE,
80485SE, 80467SE and 80505SE sensor boards is different in compari-
son to the 80418SE sensor board that was supplied with Series 2000
based systems prior to 1996 (CE Marked Systems).
The 80418SE uses the 40.2-ohm resistor on the display module to
sense the current sourced from the AD592. The compensation current
produces a voltage drop across the resistor on the display module and
then adds this voltage to the raw T/C mVs sensed at the T/C + and -
connections at the wiring board and at the sensor board.
The change was implemented on later sensor board designs (80471SE,
80485SE, 80467 SE and 80505SE) due to the confusion caused by see-
ing a display that was approximately 12 mVs higher than the voltage
measured at the terminals on the wiring board.