Teledyne GFC-7001T - Trace CO Analyzer - Manual (Page 274)

Troubleshooting and ServiceTeledyne API – Model T300/T300M CO Analyzer
Teledyne Analytical Instruments 274
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.
12.5.7.3. OPTO PICKUP ASSEMBLY
Operation of the opto pickup PCA (P/N 04088) can be verified with a voltmeter.
Measure the AC and DC voltage between digital ground on the relay board, or
touchscreen and TP2 and TP4 on the sync pickup PCA. For a working board, with the
GFC motor spinning, they should read 2.4 ±0.1 VAC and 2.5 ±0.15 VDC.
Further confirmation that the pickups and motor are operating properly can be obtained
by measuring the frequency at TP2 and TP4 using a frequency counter, a digital
voltmeter with a frequency counter, or an oscilloscope, per Table 12-9.
Table 12-9: Opto Pickup Board Nominal Output Frequencies
Nominal Measured Frequency
AC Mains Freq. TP2 TP4
50 Hz 25 300
60 Hz 30 360
12.5.7.4. GFC WHEEL DRIVE
If the D1 and D2 on the sync demodulator board are not flashing then: