Specifications

CO2 Analyzers 3100 & 3150
Instruction 19-9339 36
7.5 Calibration Method
Before you begin, ensure that the unit is stabilized at its working
temperature before performing any of the calibration operations.
To achieve the processes set out in this section, press “KEY 3 -
CALIBRATION” from the “MAIN” menu. The fi rst screen displayed
provides the option to select the gas that requires calibration.
The exact calibration method can vary depending on the gases used.
7.5.1 Zero CO
2
Channel
For maximum accuracy it is recommended that the CO
2
channel is
zeroed using bottled gas (certifi ed 100% N
2
).
If nitrogen is not available the user can select the option to perform an
air calibration. This option assumes that the user has access to fresh
air at around 390 ppm CO
2
. Generally, this can be found outside or in
a well ventilated corridor (typically, an offi ce lab would have a higher
CO
2
concentration).
To zero the CO
2
channel, perfom the following:
1) From the “CALIBRATION” menu press “KEY 2 - CO
2
CHANNEL.”