Thermo Scientific 42iQ, Инструкция по эксплуатации

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Calibration
Zero and Span Check
Thermo Scientific 42iQ Instruction Manual 4-21
2. Verify that the high NO
x
calibration gas concentration is the same as
the high NO calibration gas concentration plus any known NO
2
impurity.
3. Enter the NO
x
calibration gas concentration using the pushbuttons,
and then press Calibrate to calculate and save the new high range NO
x
span coefficient based on the entered span coefficient.
Use the following procedure to calibrate the NO
2
channel to the NO
2
calibration gas.
1. Adjust the O
3
generator in the GPT system to generate sufficient O
3
to
produce a decrease in the high NO concentration equivalent to about
80% of the URL of the high NO
2
range. The decrease must not exceed
90% of the high NO concentration determined in the “ Calibrate NOx
High ” procedure.
2. Press the Back button to return to the Calibration menu and choose
Calibrate High Range NO
2
Span Coefficient .
The user sets the span concentration by pressing the Edit Span
Concentration button. The Calculated High Range NO
2
Span
Coefficient button will show what the span coefficient will be set to if
the Calibrate button is pressed.
3. Set the high NO
2
calibration gas concentration to reflect the sum of the
NO
2
concentration generated by GPT and any NO
2
impurity using the
pushbuttons, and then press Calibrate to calculate and save the new
high range NO
2
span coefficient based on the entered span coefficient.
The analyzer requires initial and periodic calibration according to the
procedures outlined in this manual. Initially, the frequency of the
calibration procedure should be determined by the stability of the zero and
span checks, which may be run daily. You should generate a new
calibration curve when zero and span checks indicate a shift in instrument
gain of more than 10 percent from that determined during the most recent
multipoint calibration. You can adjust the frequency of calibration and
even zero and span checks appropriately as you gain confidence with the
instrument.
It is recommended to have a quality control plan where the frequency and
the number of points required for calibration can be modified on the basis
of calibration and zero and span check data collected over a period of time.
Calibrate NO
2
High
Zero and Span
Check