Teledyne API Model 200AH NOX Analyzer Instruction Manual, 06492, Rev. G2
9-17
9.1.3.4. Ozone Gen Power
This diagnostic manually turns the power off and on to the ozone generator. When the M200AH
is powered up from a cold start the ozone generator is not immediately started. This is due to the
fact that humid air may be present in the generator cartridge. Humid air can produce nitric acid
aerosol which can permanently damage parts of the instrument down stream of the generator.
Using this diagnostic, it is possible to turn on the generator before the warmup time has elapsed.
If you turn the power on it will remain on after you exit the diagnostic.
9.1.3.5. Analog Output Step Test
The Step Test is used to test the functioning of the 4 DAC outputs on the V/F board. The test
consists of stepping each analog output 0-20-40-60-80-100% of the output. If the analog outputs
are set for 0-5V full scale the outputs would step 0-1-2-3-4-5 VDC. The stepping can be halted at
any value by pressing the key under the percentage on the front panel. When the test is halted,
square brackets are placed around the percentage value in the display. Pressing the key again
resumes the test. This test is useful for testing the accuracy/linearity of the analog outputs.
9.1.3.6. DAC Calibration
The Digital to Analog Converters (DAC) are calibrated when the instrument is set up at the
factory. Re-calibration is usually not necessary, but is provided here in case the V/F board needs
to be replaced and re-calibrated. The procedure for using the DAC Calibration routines is in the
Troubleshooting Section 9.3.3.1.
9.1.3.7. RS-232 Port Test
This test is used to verify the operation of the RS-232 port. When started, it outputs the ASCII
letter X for about 2 seconds. During the test it should be possible to detect the presence of the
signal with a DVM. A detailed procedure is given in the Troubleshooting Section 9.3.2.
9.1.4. M200AH Internal Variables The M200AH software contains many adjustable parameters. Many of the parameters are set at
time of manufacture and do not need to be adjusted for the lifetime of the instrument. It is
possible to change these variables either through the RS-232 port or the front panel. Altering the
values of many of the variables will adversely affect the performance of the instrument.
Therefore it is recommended that these variables not be adjusted unless you have a clear
understanding of the effects of the change. Table 9-5 contains a description of each variable and
a brief description of its function.