Teledyne 100AH instruction manual 10-5, Pmt

Teledyne API Model 100AH SO2 Analyzer Instruction Manual, 02417, Rev. D

Table 10-1: Test Functions (Continued)

Test Function	Factory Set-Up	Comment
PMT	0 - 5000 mV	This is the instantaneous output of the PMT.
		The PMT voltage values will be relatively constant when:
		1.	Electric test - variation in the 2000 mV signal observed will
			be noise of the V/F board and preamp noise. See Section
			10.1.3.2.
		2.	Optic test - variation in the 400 mV signal will be PMT
			dark current, preamp, HVPS, and electronic. See Section
			10.1.3.3.
		3.	Sampling zero gas.
		4.	Sampling stable SO2 span gas.

When sampling zero gas the PMT reading should be less than 50 mV and relatively constant.

High or noisy readings could be due to:

1.Pneumatic leak.

2.Excessive background light which is caused by a possible aging UV filter.

3.Low UV lamp output.

4.PMT recently exposed to room light. It takes 24-48 hours for the PMT to adapt to dim light.

5.Light leak in reaction cell.

6.Reaction cell contaminated.

7.Vacuum pressure reading not stable.

8.HVPS not stable.

(table continued)

10-5