Teledyne 9110AH, Instruction Manual, Page: 121 / 181

TELEDYNE Model 9110AH NO
X
Analyzer Operator Manual, 01620, Rev. F
9-5
Table 9-1: Test Functions (Continued)
Test Function Factory Set-Up Comment
OZONE FL 250 cc/min 25 This is the Ozone flow. It is measured by a solid state flow meter,
and thus is a true indication of flow.
If you suspect there is no ozone being generated, disconnect the tube
at the reaction cell and rub the end of the tube on your fingertips, then
sniff your fingers. The odor of ozone should be readily apparent.
PMT 0-5000 mV This is the instantaneous output of the PMT. During normal operation
the value varies widely as the M9110AH switches from NO to NO
x
modes. Changes in reading will be synchronized with valve switching.
The PMT voltage values will be relatively constant when:
1. Electric test - variation in the 2000 mV signal observed will be
sampling errors of the V/F board and preamp noise. See Section
9.1.3.2.
2. Optic test - variation in the 100 mV signal will be PMT dark
current, preamp, HVPS plus item 1 above. See Section 9.1.3.3.
3. Sampling zero gas - signal from 1, 2 plus signal from ozone
generator air
4. Sampling pure NO span gas - signal will be 1, 2, 3, above plus
signal from chemiluminescent reaction. Slight pulsation’s will be
noticed as the M9110AH switches from NO to NO
x
. This is due
to differences in flowrates (Cv) in each channel. These
differences are taken out in the calibration process resulting in
slightly different slopes for the NO and NO
x
channels. Large
pulsation’s when switching to the NO
x
channel is indicative of a
bad converter.
5. 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. Electric test - variation in the 2000 mV signal observed will be
sampling errors of the V/F board and preamp noise. See Section
9.1.3.2.
2. Excessive background light which is caused by a possible
contaminated reaction cell.
3. Humidity (undried ambient air) in the ozone generator feed air.
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.
Miswiring of the thermoelectric cooler causing the PMT to be
heated.
(table continued)