Teledyne T300, Operation Manual, Page: 283 / 426

Teledyne API – Model T300/T300M CO Analyzer Troubleshooting and Service
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12.5.7. SENSOR ASSEMBLY
12.5.7.1. SYNC/DEMODULATOR ASSEMBLY
To verify that the Sync/Demodulator Assembly is working, follow the procedure below:
1. Verify that D1 and D2 are flashing.
•
If not, check the opto pickup assembly, Section 12.5.7.3 and the GFC Wheel
drive, Section 12.5.7.4.
•
If the wheel drive and opto pickup are working properly then verify that there is
2.4 ±0.1 VAC and 2.5 ±0.15 VDC between digital ground and TP 5 on the
sync/demod board. If not then check the wiring between the sync/demod and
opto pickup assembly (see interconnect drawing, P/N 04216). If good then the
sync/demod board is bad.
2. Verify that the IR source is operating, Section 12.5.7.5.
3. With the analyzer connected to zero air, measure between TP11 (measure) and
analog ground, and TP12 (reference) and analog ground.
•
If they are similar to values recorded on the factory data sheet then there is likely
a problem with the wiring or the A/D converter.
•
If they are not then either the sync demodulator board or the IR-photodetector are
bad. See Section 12.4.1.4 for problems with the IR-photodetector TEC drive.
12.5.7.2. ELECTRICAL TEST
The electric test function substitutes simulated signals for CO MEAS and CO REF,
generated by circuitry on the sync/demod board, for the output of the IR photo-detector.
While in this mode the user can also view the same test functions viewable from the
main
SAMPLE display. When the test is running, the concentration reported on the
front panel display should be 40.0 ppm. Also see Section 5.9.4.
SAMPLE RANGE=50.0 PPM CO= XX.XX
<TST TST> CAL SETUP
SETUP X.X SECONDARY SETUP MENU
COMM VARS DIAG EXIT
SETUP X.X PRIMARY SETUP MENU
CFG DAS RNGE PASS CLK MORE EXIT
DIAG SIGNAL I/O
PREV NEXT ENTR EXIT
SETUP X.X ENTER PASSWORD
8 1 8 ENTR EXIT
Continue pressing NEXT until ...
DIAG OPTIC ELECTRICAL TEST
PREV NEXT ENTR EXIT
DIAG ELEC RANGE=50.0 PPM CO= 40
<TST TST> CAL EXIT
Press <TST TST> to view Test Functions.
NOTE: CO MEAS and CO REF will be artificially altered
to enforce a CO reading of 40.0 ppm.
All other Test Functions will report the correct
operational value.
06864B DCN6314