CO2 Analyzers 3100 & 3150
Instruction 19-9339
33
7.0 Calibration
7.1 User Calibration
The instrument is fully calibrated during manufacture and when
returned for service. However, to improve accuracy between services,
a user /
fi
eld calibration can be performed.
User calibration is a means of optimizing the performance of the
instrument to the current operating conditions, such as ambient
temperature and pressure, as well as correcting for instrument drift
caused by lamp and
fi
lter settling.
In general, the instrument should not require calibration more than
once a month, but we do recommend verifying the instrument’s
operation each day
User calibration has two operations and each may be performed
individually, however, for a complete user calibration both must be
completed.
This section describes the correct procedures to achieve an accurate
user calibration.
NOTE:
If the calibration is completed incorrectly it may decrease the
accuracy of the instrument.
Two important terms that are used within this section are “Zero” and
“Span.”
Zero:
The point at which the instrument is calibrated when there
is no gas present.
Span:
The point at which the instrument is calibrated when a
known quantity of the target gas is present.
