Thermo Scientific 49i, Instruction Manual, Page: 143 / 314

Calibration
Calibration Photometer System Preparation
Thermo Fisher Scientific Model 49
i
Instruction Manual 4-7
Use the following procedure to check that the calculations are complete and
accurate.
1. With the ozone generator in the manual mode (gain set to zero), adjust
ozone level to generate a level in excess of 0.5 ppm. Wait until ozone
concentration is stable.
2. From the Service Mode menu, select Intensity Check. From the
Intensity Check menu, select Int A Reference Gas. Wait for stable
frequency reading and note as Io(A). Press
to return to the
Intensity Check menu.
3. From the Intensity Check menu, select Int A Sample Gas. Wait for
stable frequency reading, note as I(A). Press to return to the
Intensity Check menu.
4. From the Intensity Check menu, select Int B Reference Gas. Wait for
stable frequency reading, note as Io(B). Press three times to
return to the Main Menu.
5. From the Main Menu choose Diagnostics. From the Diagnostics menu
choose Temperatures to get the current bench temperature and Pressure
to get the current pressure reading.
6. Compute C(A) and C(B) from Equation 4.
This value should agree with the value noted in the Run screen. Note that
the concentration determined in this manner does not correct for lamp
fluctuation and thus will be noisier than the concentration determined in
the Run screen.
Intercomparability Test
To perform an intercomparability test of a Model 49 i Primary Standard, it
may be necessary to have the Model 49 i Primary Standard sample ozone
from a source other than the one contained in the instrument. Use the
following procedure to accomplish this.
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