Calibration - Michell Instruments XTP501 User Manual

XTP501 & XTC501 User's Manual
3

CALIBRATION

Factory Calibration:
The unit is factory calibrated at 5 points 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 then the lowest concentration will replace
the Zero Point.
NOTE: Analyzers are calibrated in background gas suitable for the specific
application. Customer's calibration gases must match the process gas. Please
refer to Test Result Sheet or a Michell Instruments' representative.
For range 0 to 25% the analyzer will have calibration points between 0 and
21% and will retain specification up to 23% O
and 25% O
(adjusts) the unit with a calibration gas of 25%.
Field Calibration:
This analyzer 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; however, it is recommended to calibrate the
unit at least every 6 months. 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.
Preparation:
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.
The calibration gas applied to the analyzer should be at the same temperature pressure
and flow rate as the process gas being sampled.
Sample Inlet Pressure: 0.75 to 1.5 BarA (10 to 20 psiA)
Sample Flow Rate:
100 to 500 ml/min (0.2 to 1.06 scfh)
Michell Instruments
are extrapolated values, unless the operator Field Calibrates
2
CALIBRATION
. Concentrations between 23%
2
27