INFICON Extrima Ex-certified Hydrogen Leak Detector - Manual (Page 35)

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EN
INFICON - Operating Instructions EXTRIMA
The Leak Rate Unit is a text string defined
by the user (default: PPM). The relation
between the detector signal and the dis-
played number is set by the Calibration
Coefficient.
The Leak Rate Unit is set in the Analysis
Mode menu. Select PPM, cc/s,
cc/min, SCCM, g/a, oz/yr, mbarl/s, mm
3 /s,
mm 3 /min, Pa m 3 /s or custom.
When you select Custom you can enter
Measuring hydrogen
concentration
When measuring hydrogen concentra-
tion the detector should be calibrated
against a reference gas with a known
concentration. The reference gas should
be Hydrogen in Synthetic Air.
Set the Calibration Coefficient to the
value of the known gas concentration.
Set the Leak Rate Unit to the same unit
as the Calibration Coefficient.
Example:
A reference gas contains 10 ppm Hydro-
gen in synthetic air. Set Calibration Coef-
ficient to 10 and Leak Rate Unit to PPM.
Measuring Leak Flow
When measuring leak flow, calibrate the
detector against a reference leak.
The reference leak should have a flow
close to the chosen Leak Alarm Level.
See also section ”Selecting the reference”
on p. 36.
Set the Calibration Coefficient to the
certified value of the reference leak. Set
the Leak Rate Unit to the same unit as the
Calibration Coefficient.
Example:
A reference leak is certified to 1.5 cc/min.
Set Calibration Coefficient to 1.5 and
Leak Rate Unit to cc/min.
any unit as long as it contains a maxi-
mum of 12 characters. The unit can also
be as a concentration, for example PPM
or mg/ml-H
2
.
Calibration can be performed against:
— a known leak flow,
or
— a known hydrogen concentration.
NOTE: It is important that the unit for Leak Rate Unit is the same as for the
used leak flow/concentration. If not — convert one of the values.
Leak Rate Unit and Calibration Coefficient