Adixen ASM 142, Руководство пользователя

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C 303
External calibration of the leak detector
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Target value determination • In hard vacuum test mode, l possible case:
- The target value is the value of an external calibrated leak connected
to the installation to test or at the inlet port of the leak detector.
—>
Case A
• In sniffing test mode, 2 possible cases:
- the target value is the value of an external calibrated leak.
—>
Case A
- If a container or installation is filled with a known gas mixture
including Helium, it is possible to enter helium concentration as a
target value.—>
Case B
Case A
When an external calibrated leak is used, it is recommended to take
into account date of calibration and temperature effect for calculating
the target value from the calibrated leak value as shown on its
identification label.
HELIUM CALIBRATED LEAK
Helium leak rate : 1.0x10 -8 mbar.l/s at 20 °C
Date of calibration : 10 Dec 2001
% loss per year : 2 %
% increase per °C : 3 %
Example of calibrated leak label indications (as listed here):
If the date is lst Dec 2003 (about 2 years after calibration) and
calibrated leak (ambient) temperature is 25 °C:
Target value = l.0xl0 -8 x[l+0.03x(25-20)]x[l-(0.02x2)]
= l.lxl0 -8 mbar.l/s
Case B
Checking function with
an external calibrated
Reminder: l PPM = l.0xl0 -6 (concentration)
Example : container with l00 PPM helium mixture.
2 possibilities :
➥
enter target value = 0 E+02 to display the test result
in PPM
➥
enter target value = l.0 E-04 to display the test result in helium
concentration
(l00 PPM = l00 xl0 -6 = lxl0 -4 )
leak
C 302