Teledyne API Model 200AH NOX Analyzer Instruction Manual, 06492, Rev. G2
9-21
PMT Calibration Procedure:
NOTE
In this procedure a range of 100 ppm and a span gas concentration
of 80 ppm is used as an example. Other values can be used.
1. On the Preamp board, set S2 to 6, set S1 to 8. Turn R19 25 turns counter-clockwise, then 12
turns clockwise (see figure 2-6).
2. Set RANGE MODE to SING by pressing SETUP-RNGE-SET-MODE to select single range
operation.
3. Set the RANGE to 100 ppm by SETUP-RNGE-SET and key in 100, then press ENTR.
4. Input Zero gas into the sample port, and Scroll to the TEST function labeled NORM PMT.
The reading should be near 0mV. Readings above 50 mV indicate a pneumatic leak, light
leak, contaminated reaction cell, bad zero gas, or wet air coming into the ozone generator. If
readings are greater than 50mV the instrument will not zero or span properly see
Sections 9.2.8, 9.2.9.
5. Allow the instrument to sample zero gas for at least 10 minutes to fill the internal data filters
with zero readings. The reading is stable when the STABIL – TEST function drops to 2.0 or
less. Then zero the instrument by CAL-ZERO-ENTR.
6. Set the expected span concentration to 80 ppm. Enter the expected NOX concentration of
80 ppm by pressing CAL-CONC-NOX. Then press CAL-CONC-NO, to enter the expected
NO concentration of 80 ppm. Then press EXIT to return to the CAL menu.
7. Input 80 ppm of NO span gas in the sample inlet port.
8. Scroll to the NORM PMT - TEST function.
9. Calculate the expected PMT mV reading.
For ranges up to 500 ppm, multiply the expected span value by 8 to get the mV reading.
For ranges 501 to 5000 ppm, multiply the expected span value by .8 to get the mV reading.
In this example the expected span gas concentration is 80 ppm and therefore the expected
voltage is 80 ppm x 8 = 640 mV. As an alternate method, the voltage can be determined from
the graph in Figure 9-1. On the Y-axis find the calibration concentration in PPM, then
determine the expected voltage from the X-axis.