Calibration - Michell Instruments XTC601 User Manual

CALIBRATION

3 CALIBRATION
Factory Calibration:
The unit is factory calibrated at 5 points (per phase) to maximize the accuracy over
the desired range. The calibration generally includes Zero & Span points as well as 3
intermediate points. In the case of suppressed zero ranges the lowest concentration will
replace the Zero Point.
Field Calibration:
Like all process analyzers, the XTC601 will require periodic calibration. The frequency
entirely depends on the location, application and accuracy requirements of the user. The
typical calibration period is expected to be between 1 and 3 months. If the calibration
period is in excess of 1 month Michell recommends a Zero and Span calibration. The
user should establish a calibration frequency to ensure that the reading is within the
specifications required for the process.
NOTE: It is possible to switch off the Field Calibration and revert to the Factory
Calibration. This can be useful for diagnostic purposes if the reading is not
what is expected. The unit is delivered with a factory calibration and, as such,
would not have any field calibration data. As soon as the first field calibration
is performed, the field calibration setting is automatically switched on.
For the HCG version, the calibration settings shown apply to the currently
selected phase. In order to perform a field calibration on each phase it will be
necessary to repeat the process three times.
Preparation:
Go to Settings Page (see Section 2.7.1) and make a note of ON/OFF options for all
settings. Re-set these options after calibration.
Zero and Span gas cylinders with correct regulation and flow control should be in place
before installing and powering up the analyzer. Commissioning should include a check
with both gases and, if necessary, a field calibration performed.
All analyzers will be calibrated with an inlet pressure of 1 barg (14 psig) with an
atmospheric vent and flow rate of 300 ml/min (0.63 scfh). The calibration gas applied
to the analyzer should be at the same pressure and flow rate as the process gas being
sampled.
• Sample Inlet Pressure: 0 to 3 barg (0 to 43 psig) with atmospheric vent
• Sample Flow Rate:
26
100 to 600 ml/min (0.2 to 1.27 scfh)
XTC601 User's Manual
97400 Issue 3.1, January 2017