TELEDYNE API T703U - Fault Diagnosis with Test Functions; Table 8-2: Test Functions - Indicated Failures

Teledyne API T703/T703U Calibrator Operation Manual General Troubleshooting & Service
157
WARNING
FAULT CONDITION
POSSIBLE CAUSES
PHOTO REFERENCE
WARNING
Occurs when Ref is
<2500 mVDC
or >4950 mVDC.
Possible failure of:
- UV Lamp
- UV Photo-Detector Preamp
REAR BOARD NOT DET
Motherboard not detected on
power up.
- THIS WARNING only appears on Serial I/O COM Port(s)
Front Panel Display will be frozen, blank or will not
respond.
- Failure of Motherboard
RELAY BOARD WARN
The CPU cannot communicate
with the Relay PCA.
- I
2
C Bus failure
- Failed relay PCA
- Loose connectors/wiring
SYSTEM RESET
The computer has rebooted.
- This message occurs at power on.
- If it is confirmed that power has not been interrupted:
- Failed +5 VDC power
- Fatal error caused software to restart
- Loose connector/wiring
FAULT DIAGNOSIS WITH TEST FUNCTIONS 8.1.2.
In addition to being useful predictive diagnostic tools, the test functions viewable
from the calibrator‟s front panel can be used to isolate and identify many
operational problems when combined with a thorough understanding of the
calibrator‟s Theory of Operation (see Section 9).
The acceptable ranges for these test functions are listed in the “Nominal Range”
column of the calibrator Final Test and Validation Data Sheet shipped with the
instrument. Values outside these acceptable ranges indicate a failure of one or
more of the calibrator‟s subsystems. Functions whose values are still within the
acceptable range but have significantly changed from the measurement recorded
on the factory data sheet may also indicate a failure.
A worksheet has been provided in Appendix C to assist in recording the value of
these Test Functions.
Table 8-2 contains some of the more common causes for these values to be out of
range.
Table 8-2: Test Functions - Indicated Failures
TEST FUNCTION
DIAGNOSTIC RELEVANCE AND CAUSES OF FAULT CONDITIONS.
OUTPUT FLOW
Gas flow problems directly affect the concentration accuracy of the O
3
calibration gases.
This number is computed using data from the calibrator‟s
- Check for Gas Flow problems.
- Check the pressure regulator
O3 GEN DRIVE
Check the O
3
generator heater and temperature sensors
Possible causes of faults are the same as O3 GEN LAMP TEMP WARNING from Table 8-1
O3 LAMP TEMP
Incorrect Lamp temperature can affect the efficiency and durability of the O
3
generators UV
lamp.
Possible causes of faults are the same as O3 GEN LAMP TEMP WARNING from Table 8-1
REG PRESSURE
Same as REGULATOR PRESSURE WARNING from Table 8-1
BOX TEMP
If the Box Temperature is out of range, make sure that the:
Box Temperature typically runs ~7C warmer than ambient temperature.
- The Exhaust-Fan is running
07223D DCN7107