Teledyne API – Model T300/T300M CO Analyzer
Troubleshooting and Service
263
11.5.7.
SENSOR ASSEMBLY
11.5.7.1.
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 11.5.7.3 and the GFC Wheel
drive, Section 11.5.7.4.
•
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 11.5.7.5.
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 11.4.1.4 for problems with the IR-photodetector TEC drive.
11.5.7.2.
ELECTRICAL TEST
The electric test function substitutes simulated signals for CO MEAS and CO REF,
generated by circuitry on the sync/demod board. This function tests the filtering and
amplification of that assembly along with the A/D converter on the motherboard. It
should be noted that this will not test the IR photo detector itself. 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 at or near 40.0 ppm.
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.
06864D DCN7562
Summary of Contents for T300
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