Teledyne MODEL T703 Photo Scanner User Manual


 
General Troubleshooting & Repair Teledyne API T703 Calibrator Operation Manual
210
11.4.12.4. Ozone Generator Temperature
There are three possible causes for the Ozone Generator temperature to have failed.
The O
3
generator heater has failed. Check the resistance between pins 5 and 6 on the 6-pin connector
adjacent to the UV Lamp on the O
3
Generator. It should be approximately 5 Ohms.
Assuming that the I
2
C bus is working and that there is no other failure with the Relay board, the FET
Driver on the Relay Board may have failed. Using the O3_GEN_HEATER parameter under the SIGNAL
I/O function of the DIAG menu, as described above, turn on and off the UV Lamp Heater. Check the DC
voltage present between pin 1 and 2 on J14 of the Relay Board.
If the FET Driver has failed, there should be no change in the voltage across pins 1 and 2.
If the FET Driver checks out OK, the thermistor temperature sensor in the lamp assembly may have
failed. Unplug the connector to the Ozone Generator Heater/Thermistor PCB, and measure the
resistance of the thermistor between pins 5 and 6 of the 6-pin connector.
11.5. TROUBLESHOOTING THE O
3
PHOTOMETER
11.5.1. DYNAMIC PROBLEMS WITH THE O
3
PHOTOMETER
Dynamic problems are problems, which only manifest themselves when the photometer is measuring O
3
concentration gas mixtures. These can be the most difficult and time consuming to isolate and resolve.
Since many photometer behaviors that appear to be a dynamic in nature are often a symptom of a seemingly
unrelated static problems, it is recommended that dynamic problems not be addressed until all static problems,
warning conditions and subsystems have been checked and any problems found are resolved.
Once this has been accomplished, the following most common dynamic problems should be checked.
11.5.1.1. Noisy or Unstable O
3
Readings at Zero
Check for leaks in the pneumatic system as described in Section 10.2
Confirm that the Zero gas is free of Ozone.
Confirm that the Source Lamp is fully inserted and that the lamp hold-down thumb- screw is tight.
Check for a dirty Absorption Cell and/or pneumatic lines. Clean as necessary as described in Section
10.2
Disco
nnect the exhaust line from the optical bench (the pneumatic line at the lamp end of the bench) and
plug the port in the bench. If readings remain noisy, the problem is in one of the electronic sections of the
instrument. If readings become quiet, the problem is in the instrument's pneumatics.
07223B DCN6378