Thermo Scientific 49i, Instruction Manual, Page: 146 / 314

Calibration
Calibration Procedure
4-10 Model 49
i
Instruction Manual Thermo Fisher Scientific
If a strip chart recorder is used, it is recommended that it be adjusted to
obtain a record of zero drift and/or zero noise. This can be achieved by
using the zero offset capability of the recorder.
5. Record the stable zero air response as Z.
Span Adjust
Use the following procedure to adjust span.
1. Generate an ozone concentration standard of approximately 80% of the
upper range limit (URL) of the ozone analyzer (such as, 0.4 or 0.8 ppm
for the 0.5 and 1.0 ppm ranges respectively).
2. Allow the instrument to sample this ozone concentration standard until
a stable response is obtained.
3. From the Main Menu choose Calibration > Calibrate Span . Use
and to increment/decrement the known span gas concentration.
Press to calibrate the instrument.
The recorder response will equal:
where:
URL = Upper range limit of the Model 49 i , ppm
Z = Recorder response with zero air, % scale
[O
3
]
out
= Ozone concentration as determined by the calibration photometer, ppm
4. Record the ozone concentration as determined by the calibration
photometer and the corresponding analyzer response.
Additional Concentration
Standards
1. Generate several other ozone concentration standards (at least five others
are recommended) over the scale range of the instrument.
Z 100
URL
) (O
(%Scale) sponse RecorderRe
out 3
u
(5)