Teledyne API Model 200AH NO
X
Analyzer Instruction Manual, 06492, Rev. G2
9-4
Table 9-1: Test Functions (Continued)
Test Function Factory Set-Up Comment
SAMPLE FLW
290 cc/min
30
This is the instrument flow. It is computed using the up stream and
down stream pressures across the sample and bypass flow orifices.
This method can give a false flow indication if the orifice is
plugged and the sample pump is creating a pressure drop. It should
be taken into account when diagnosing instrument faults.
- A rapid method of determining if the orifice is plugged is to
disconnect the sample, bypass or ozone tubes upstream of their
respective locations, then briefly put your finger over the fitting.
You should feel the vacuum build up. The bypass flow should be
250 cc/min, the ozone 250 cc/min, and sample flow of 50 cc/min.
- Another reliable method is to attach a rotameter or soap bubble
flowmeter to the fittings to measure the flow.
Flow rate will change
a few cc/min due to changes in ambient air
pressure such as cycling of air conditioning, or passing weather
fronts. Changing altitude changes the ambient air pressure and
therefore the sample flowrate. This effect is about 15-20 cc/min per
1000 feet of altitude change. If required, the output of the
instrument can be compensated for pressure. See Section 5.3.9,
Table 9-5.
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.
(table continued)
