Michell Instruments XZR500ST, User Manual

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XZR500 User’s Manual
Michell Instruments 29
OPERATION
3.3.3 Calibration [+]
The XZR500 has been designed for simple operation. The calibration procedure is
extremely easy and can be performed within minutes. The analyzer is self-adjusting
during calibration. There are only a few steps that need to be carried out for the actual
calibration procedure.
3.3.3.1 Recommended Calibration Gas
NOTE: Please make sure that only gas of a known composition is used for
calibration of the XZR500. The gas cylinder must be certi fi ed as to the exact
composition of the calibration gas.
Michell recommends the following calibration gas concentrations that can be ordered
from your analyzer vendor.
• 1G Calibration Kit with one gas cylinder (nitrogen with 8% oxygen
concentration)
• 2G Calibration Kit with two gas cylinders (nitrogen with 8% oxygen
concentration for calibration and nitrogen with 2% oxygen concentration
for veri fi cation)
CALIBRATION GAS UNCERTAINTY:
Observe the uncertainties of the calibration gas when
calculating the overall analyzer uncertainty. Any uncertainty
of the oxygen content of the calibration gas may introduce
considerable error in the calibration of the analyzer.
NOTE: Prior to calibration, make sure that the ‘Test gas value’
in the access code 0.12 of the analyzer menu is the same as
the calibration gas value.
3.3.3.2 Regulating the Calibration Flow Rate
In order to perform the calibration it is recommended to arrange a temporary connection
with a regulator and isolation valve located at the calibration gas inlet on the analyzer.
Make sure the connection is as short as possible. A regulator and isolation valve are
supplied in the calibration kit.
Connect the calibration kit or your test gas cylinder to the calibration gas inlet (Figure
4 (12)). Use 1/8” tube and
fi tting. NOTE: Ensure a fl ow of 7 l/hour (±2 l/hour)
(0.12 to 0.18 l/min).
NOTE: Tighten up the stainless steel locking nut by hand and then tighten again
using a 7/16" spanner, for 1/8th turn so as not to damage the connection.
NOTE: During calibration the output signal is frozen at the last value measured
before the beginning of the calibration procedure.