Teledyne 9110T - Nitrogen Oxides Analyzer - Manual (Page 289)

Model 9110T NOx Analyzer Troubleshooting & Service
Teledyne Analytical Instruments 289
12.7.7. PRESSURE / FLOW SENSOR ASSEMBLY
The flow and pressure sensors of the 9110T are located on a PCA just behind the PMT sensor (see
Figure 3-5) can be checked with a Voltmeter.
Figure 12-6: Pressure / Flow Sensor Assembly
The following procedure assumes that the wiring is intact and that the motherboard and power supplies
are operating properly:
12.7.7.1. Basic PCA Operation Check:
 Measure the voltage between TP2 and TP1 C1 it should be 10 VDC ± 0.25 VDC. If not then the
board is bad. Replace the PCA.
12.7.7.2. Sample Pressure Sensor Check:
1. Measure the pressure on the inlet side of S1 with an external pressure meter.
2. Measure the voltage across TP4 and TP1.
 The expected value for this signal should be:
EXAMPLE: If the measured pressure is 20 Hg-in-A, the expected voltage level between TP4 and TP1
would be between 2870 mVDC and 3510 mVDC.