Teledyne API T802 Paramagnetic O2 Analyzer Operation Manual Troubleshooting and Service
211
11.6.6. RELAY BOARD
The relay board PCA (04135) can be most easily checked by observing the
condition of the its status LEDs on the relay board, as described in Section
12.5.4.1, and the associated output when toggled on and off through signal I/O
function in the diagnostic menu, See Section 11.1.3.
1. If the front panel display responds to key presses and D1 on the relay board
is NOT flashing then either the wiring between the Keyboard and the relay
board is bad, or the relay board is bad.
2. If D1 on the relay board is flashing and the status indicator for the output in
question (heater power etc.) toggles properly using the signal I/O function,
then the associated control device on the relay board is bad. (Several of the
control devices are in sockets and can be easily replaced).
11.6.7. SENSOR ASSEMBLY
The paramagnetic O2 sensor of your T802 analyzer has no user serviceable parts
11.6.8. PRESSURE/FLOW SENSOR ASSEMBLY
The pressure/flow sensor PCA can be checked with a Voltmeter using the
following procedure which, assumes that the wiring is intact, and that the
motherboard and the power supplies are operating properly:
1. For Pressure related problems:
Measure the voltage across C1 it should be 5 ± 0.25 VDC.
If not then the board is bad.
Measure the voltage across TP4 and TP1.
With the sample pump disabled it should be 4500 mV ±250 mV.
With the pump energized it should be approximately 200 mV less. If
not, then S1, the pressure transducer is bad, the board is bad, or there
is a pneumatic failure preventing the pressure transducer from sensing
the absorption cell pressure properly.
2. For flow related problems:
Measure the voltage across TP2 and TP1 it should be 10 ±0.25 VDC.
If not then the board is bad.
With flow stopped (sample inlet blocked) the voltage should be
approximately 1V.
If the voltage is incorrect, the flow sensor is bad, the board is bad or
there is a leak upstream of the sensor.
07275B DCN6418