Thermo Scientific 42iQLS, Instruction Manual

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Calibration
Calibration
Thermo Scientific 42iQLS Instruction Manual 4-9
3. Be sure the instrument is in the auto mode, that is, NO, NO
2
, and
NO
x
measurements are being displayed on the front panel display. If
the instrument is not in auto mode:
a. From the Home screen choose Settings>Measurement
Settings>Advanced Measurement Settings>Auto/Manual Mode .
b. Select NO/NOx .
4. Check the averaging time. It is recommended that a higher averaging
time be used for best results.
a. From the Home screen choose Settings>Measurement
Settings>Averaging time . (Ensure Dynamic Filtering is disabled to
access Averaging Time.)
Note The averaging time should be less than the zero duration and less
than the span duration.
▲
5. Verify that any filters used during normal monitoring are also used
during calibration.
The following procedure calibrates the analyzer using the gas phase titrator
and zero in gas generator described previously in this manual. It is
suggested that a calibration curve have at least seven points between the
zero and full scale NO concentrations. Although the seven-point curve is
optional, two of whatever number of points is chosen should be located at
the zero and 90% levels and the remaining points equally spaced between
these values.
Note When the instrument is equipped with internal zero/span and sample
valves, the ZERO IN and SPAN ports should give identical responses to
the SAMPLE port when test gases are introduced. The user should calibrate
the instrument using the SAMPLE port to introduce the zero and span gas
sources.
▲
After calibration, the zero in and span sources should be plumbed to the
appropriate ports on the rear panel of the instrument, and then
reintroduced to the instrument. The instrument should give identical
responses to the test gases whether they are introduced via the SAMPLE
port or the ZERO IN or SPAN ports. If not, the plumbing and/or valves
should be serviced.
Calibration