Calibrate Span Coefficient - Thermo Scientific 48iQ Instruction Manual

Calibration
Calibration
Calibrate Span
Coefficient
4-10 48iQ Instruction Manual
Use the following procedure to adjust the span.
1. Adjust the zero air flow and the CO flow from the standard CO
cylinder to provide a diluted CO concentration of approximately 80%
of the upper range limit (URL) of the analyzer.The total air flow must
exceed the total demand of the analyzer connected to the output
manifold to ensure that no ambient air is pulled into the manifold vent.
The exact CO concentration is calculated from:
[CO
Where:
[CO] = diluted CO concentration at the output manifold, ppm
OUT
[CO] = concentration of the undiluted CO standard, ppm
STD
F = flow rate of CO standard corrected to 25 °C and 760 mmHg, L/min
CO
F = flow rate of dilution air corrected to 25 °C and 760 mmHg, L/min
D
2. Allow the instrument to sample this CO concentration standard until a
stable response is obtained.
3. From the Home Screen, choose Calibration>Calibrate Span
Coefficient.
The user sets the span concentration by pressing the Edit Span
Concentration button. The Calculated Span Coefficient button will
show what the span coefficient will be set to if the Calibrate button is
pressed. Pressing the Calibrate button will save the new coefficient and
calibrate the instrument.
4. Enter the CO calibration gas concentration using the pushbuttons, and
then press Calibrate to calibrate the CO reading to the CO calibration
gas.
5. Record the CO concentration and the instrument's response.
( [CO x
]
F
CO
STD
] =
OUT
( + )
F F
D CO
)
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