Thermo Scientific 43iQ, Instruction Manual

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Calibration
Manual Calibration
Thermo Scientific 43iQ Instruction Manual 4-11
b. Make sure that the reported sample flow is less than the actual zero
air flow.
3. Monitor the zero air reading and wait for the reading to stabilize.
4. Record the measured SO
2
value as the zero drift since the last
adjustment. If the zero has changed by more than ±0.015 ppm, it is
recommended that a new calibration be performed.
5. Connect a source of vented span gas to the SAMPLE bulkhead. The
span gas should be approximately 80% of the full-scale range.
6. To ensure that the span gas is being measured at atmospheric pressure
check that the flow is approximately 0.5 LPM or more, with the excess
flowing out the atmospheric bypass.
7. Sample the vented calibration gas and wait for the instrument reading
to stabilize.
8. Record the difference between the measured SO
2
value and the actual
SO
2
span concentration used. This is the span drift since the last
adjustment. If the calibration has changed by more than ±10%, a new
calibration should be performed.
The Manual Calibration screen allows the user to view and manually adjust
the zero background and span coefficient. These are used to correct the
SO
2
readings that the instrument generates using its own internal
calibration data.
Normally, the zero background and span coefficient are calculated
automatically at the Calibrate Background and Calibrate Span Coefficient
described earlier in the chapter. However, the calibration factors can also be
set manually using the functions as described below.
The following screen is shown in single range mode. In dual or auto range
modes, “High Range” or “Low Range” buttons are displayed to indicate the
calibration of the high or low coefficient. The Adjust High Range Span
Coefficient and Adjust Low Range Span Coefficient screens function the
same way.
Manual
Calibration