Servicing; Checking Sensor Operation - AGFA Avantra 36/44 Service Manual

Avantra 36/44 Service Manual
4.2

Servicing

4.2.1 Checking Sensor Operation

When reading the following procedures, refer to the low voltage wiring diagram.
4.2.1.1 Optical Interrupter
1. Check the +5 V supply. Connect the DVM between P31,4 (common) and
P31,2 (+).
Reading should be 4.75 to 5.25 V DC.
2. Check the supply to the transmitter. Connect the DVM between P31,4
(common) and P 31,3 (supply) of the optical interrupter.
Reading should be 1.7 to 1.9 DC.
3. Connect the DVM between P31,4 (common) and P31,1 (pulse) of the opti-
cal interrupter.
Reading should range from 12 V (detector gap open) to 0 V (detector gap
closed).
4.2.1.2 Film Sensor
1. Check the output. Connect the DVM across the appropriate channel to be
checked.
For SENSOR 4, for example, measure the voltage between X501,15 and
X501,2. A non activated sensor should read 0 V, and an activated sensor
should read 5 V.
4.2.1.3 Temperature Sensor
Checking the response to the actual temperature is done as a resistance measure-
ment.
1. Switch off the processor.
2. Disconnect the sensor from the circuit.
3. Connect a DVM to the sensor.
4. Use the following (simplified) formula to calculate the correlation between
temperature and resistance:
Resistance (Q) = (temp. [C ° ] x 1.925) + 500
4-2 Maintenance