ThermoFisher Scientific 146iQ, Instruction Manual

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Calibration
Calibration of the Photometer
Thermo Scientific 146iQ Instruction Manual 4-7
The accuracy of the ozone concentrations generated in the 146iQ is
dependent on the accuracy of the internal photometer when the internal
photometer is used to calibrate the ozone generator or when it is used in
feedback control of the ozone output in normal operation. The calibration
of the photometer requires an external zero air source (ZERO) and ozone
source (SPAN), as well as an external reference photometer to validate the
zero and span concentrations. These sources should be capable of providing
the flow required by the internal photometer in addition to that of the
external reference photometer. The procedure for calibration of the internal
photometer is as follows:
1. Connect the external ZERO/SPAN source to the bulkhead labeled
‘External Sample’ on the rear panel.
2. Set the Internal Photometer to ‘External’ mode as shown below in
Settings>
Operation :
3. From the Home Screen, press Calibration> Photometer Calibration . It
is recommended that the averaging time for the photometer be set to a
sufficiently long value, such as 300 seconds to obtain an optimal
calibration.
4. Ensure that the external zero air is activated, and the photometer
readings have stabilized prior to going to Calibration>Photometer
Calibration>
Calibrate Background to perform a background
calibration of the photometer. Alternately, a manual background
calibration can also be accomplished via Calibration>Photometer
Calibration>Advanced Photometer Calibration>Manual
Calibration>
Adjust Background (Details in the ‘ Operation ’ Chapter).
Confirm that the external reference photometer is also reading ~ 0.0
ppb.
Calibration of
the Photometer