F-900 Instruction Manual rev. 1/16/2014
1554 NE 3
rd
Ave, Camas, WA 98607, USA Phone (360) 833-8835 Fax (360) 833-1914
[email protected] http://www.felixinstruments.com
25
CO
2
Calibration
To access the Calibrate CO
2
feature of the F-900, press the RIGHT arrow key when Calibration is
highlighted on the Setup Menu. Press enter to continue to the Calibration mode.
The CO
2
sensor (IRGA or ER) needs to be enabled in the SETUP<SENSOR menu to access the
SETUP<CO
2
menu. To calibrate the IRGA CO
2
sensor, 400 ppm or 600 ppm standard CO
2
gas is
recommended. To Calibrate the Extended Range CO
2
, 4% CO
2
is recommended.
Calibration Parameters will display the coefficients from the previous calibration.
Re-Calibration allows the user to re-calibrate the sensor, setting a new zero and span for the
selected sensor. IRGA CO
2
Re-Calibration is recommended weekly. Extended Range CO
2
Re-
Calibration is recommended monthly. However, if the unit is in an environment where the
temperature fluctuates frequently, re-calibration may be necessary more often than the
recommended intervals.
Turn the ethylene (C
2
H
4
) sensor on for the CO
2
calibration. Directions for using a buffer system in
place of a standard gas may be found at the end of the section.
Figure 11: Calibrating the CO
2
sensor using standardized gas.
The IRGA CO
2
zero calibration will drift with time and temperature therefore weekly calibration is
recommended when using the IRGA CO
2
sensor. The CO
2
span calibration should be performed
immediately after the CO
2
zero calibration. When performing the CO
2
span calibration, use
