Teledyne t320u Manuale Utente

Teledyne API – Model T300/T300M CO Analyzer 

Troubleshooting and Service 

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. 

 

06864B DCN6314