GasCheck G Instrument User Manual V2.4
Unrivalled Gas Detect
ion.
Page 20 of 26
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Calibration
Over view
The GasCheck G has two selectable calibration settings; Factory
and Custom. 'Factory Calibration' is carried out at Ion Science
Ltd/ Authorised Service Centres during the instruments
manufacture and during annual calibration, it can be selected
and used but can not be changed.
The GasCheck G is calibrated against a 5000 ppm Helium
concentration and a 0.0005cc/sec (5 E-4) Helium leak rate.
'Custom Calibration' gives the user the ability to calibrate the
instrument. This facility may offer improved accuracy over the
'Factory Calibration' if the Barometric air pressure differs from
that stated on the instruments Calibration certificate.
Selecting Factory or Custom Calibration
To select either Factory or Custom Calibration select the Calibration
screen and user the UP and DOWN keys to move the 'tick / check'
under the desired symbol, then Press the 'Esc' key to exit into the
main menu.
'Custom Calibration' can only be selected and use after the instrument has been calibrated by the user, to do this
move the 'tick / check' under the 'Custom Cal' symbol and press the ENTER key.
The GasCheck G requires either 5000 ppm Helium concentration or a 0.0005cc/sec (5 E-4 cc/sec) leak rate as a
reference. The GasCheck G automatically selects the type of Calibration media based on which units the instrument
already has selected.
If the GasCheck G is used to detect leaks measured using 'ppm or mg/m
3
' units then the instrument must be calibrated
using a 5000 ppm Helium concentration.
If the GasCheck G is used to detect leaks measured using 'cc/sec' units then the instrument must be calibrated using a
0.0005 cc/sec (5 E-4) Helium leak.
Calibration procedure using 'ppm' units
Please read this entire procedure before proceeding with this calibration routine.
1.
Fill an empty (uncontaminated) sample bag with 5000 ppm Helium gas before
starting the calibration procedure. Also remove the outer grey probe from the
GasCheck G.
2.
Select the 'Custom Cal' symbol from the instruments menu. An option appears
allowing the adjustment of the 'ppm' value to ensure the instrument matches the
gas concentration being used. Use the UP and DOWN keys to adjust between 4900
and 5100 ppm.
3.
Ensure the instrument is in clean air and then press the ENTER key, the instrument
will Zero, this will take a few seconds but once complete a 'Ready' message will
appear.
4.
Insert the instruments probe fully into the sample bag containing the gas and press
the ENTER key. The instrument will automatically sequence through the cold and
hot stages of calibration but when finished gives a summary of values.
5.
Press the ENTER key to return back to the calibration option screen. Press the ESC
key to start using the instrument or press the ENTER key to calibrate again.
