Functional description
5
gas-lab
Q1
Page 33
5.1.2 Calibration
Each
gas-lab
Q1 measuring system has been calibrated when being delivered,
i.e. the device has been calibrated by the manufacturer. During operation an
automatic calibration with methane (1-point calibration) is carried out
periodically. During the routine testing of the device after one year, we
recommend to perform a manual basic calibration with nitrogen, methane and
two other calibration gases (3-point calibration).
5.1.2.1
1-point calibration / automatic calibration
Precondition for a successful completion of a 1-point calibration is that the
methane is properly connected on gas path 2 (see Cylinder change 5.1.4).
For this purpose the cylinder regulator must set be to approx 2 bars and the
precision pressure regulator (M2R) of the second gas path must be set to about
80 mbars. If the methane cylinder is not already opened, open it now and do a
purging right after it (see 5.1.5). Also the corresponding shut-off valve must be
opened.
It is
not necessary to open
the calibration switch at the
gas-lab
Q1 for this
calibration type.
An automatic 1-point calibration with methane can be carried out during normal
measuring in the following conditions:
In a fixed, configurable cycle every 1, 2, 3, 4, 5 or 6 days or 1, 2, 4, 8 or 12
weeks on a specified day
at xx o’clock, typically every 7 days.
After a configurable time in hours after each switching on of the supply
voltage for the evaluation computer or sensor system, typically 12 hours
later.
After a configurable time in hours after each manual purge of a gas path,
typically 12 hours later.
After a configurable time in hours after errors that may affect the
measurement have been cleared, for instance
Pressure disturbed
evaluation computer (A607)
, typically 12 hours later.