MSA PrimaX IR Manual De Operación página 22

Start-up and Calibration MSA
Fig. 10 HART control system
Although both a full calibration [zero and span] and zero only calibration can be per-
formed on the device, a zero only calibration may be sufficient to properly calibrate
the monitor. Normally, any degradation of the sensor's performance is associated
with slight drifts in zero that, in turn, will adversely affect its span performance. After
completing the zero calibration, perform a span check to ensure proper operation.
For a span check, apply a gas of known concentration and verify that the measured
response is within acceptable limits. If the span check is unsuccessful, perform a
full zero and span calibration.
Alternate Span Gas Settings
To achieve the most accurate calibration it is always best to use the gas of interest
and calibrate at the operating temperature. If the target span gas is not available,
an alternative span gas can be used with the values shown in the table below. The
sensor label will identify the span gas and value used by the factory for calibration.
Use of a reference gas for calibration may decrease accuracy.
The user may change the gas monitor's span value, gas name and gas curve
through use of the PrimaX IR Link software found on the product CD. Please refer
to the PrimaX IR HART Specification and the PrimaX IR Link Help Guide on the
product CD.
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PrimaX IR