Thermo Scientific 49iQ, Instruction Manual

Page: 164 / 282

Calibration
Manual Calibration
4-16 49iQ Instruction Manual Thermo Scientific
The Manual Calibration screen allows the user to view and manually adjust
the zero background and span coefficient. These are used to correct the O
3
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 as the (single range) Adjust Span Coefficient screen.
Home Screen>Calibration>Advanced Calibration>Manual Calibration
(single range mode)
The O
3
background is the amount of signal read by the analyzer while
sampling zero air.
The Adjust Background screen is used to perform a manual zero
background calibration of the instrument. As such, the instrument should
sample zero air until stable readings are obtained. The button labeled
Adjust Background allows the user to change zero background. The second
button shows the current background and the Adjusted Concentration
shows what the new O
3
concentration would be based on the changed zero
background. Press the Calibrate button to save the adjusted zero
background value.
Manual
Calibration
Adjust Background