Teledyne API Model 200AU NOX Analyzer Instruction Manual, 02293, Rev. F
9-23
9.1.6 Factory Calibration Procedure This procedure is similar to that used at the factory when the instrument is first manufactured, it
balances the PMT, preamp, and software gain factors so the instrument has optimum noise,
linearity, and dynamic range. It should be used when you are unable to zero or span the
instrument, when the slope and offset values are outside of the acceptable range, or when other
more obvious reasons for problems have been eliminated.
Factory Calibration Procedure:
NOTE
In this procedure a range of 500 ppb and a span gas concentration
of 400 ppb is used as an example. Other values can be used.
1. On the Preamp board, set S1 and S2 to 8. Turn R19 25 turns counter-clockwise, then 12
turns clockwise.
2. Set RANGE MODE to SNGL by SETUP-RNGE-MODE-SNGL to select single range
operation.
3. Set the RANGE to 500 ppb by SETUP-RNGE-SET and key in 500, then press ENTR.
4. Input Zero gas into the sample port, and Scroll to the TEST function labeled PMT.
Typical reading should be less than 50 mV. Readings above 150 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 ± 150 mV, 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 20 minutes to re-fill the internal data
filters and Pre-reactor filter with zero readings. Then zero the instrument by CAL-ZERO-
ENTR.
6. Set the expected span concentration to 400ppb. Enter the expected NOx concentration of
400 ppb by pressing CAL-CONC-NOX. Then press CAL-CONC-NO, to enter the expected
NO concentration of 400 ppb. Then press EXIT to return to the CAL menu.
7. Input 400 ppb of NO span gas in the sample inlet port.
8. Scroll to the NORM_PMT - TEST function.