Vaisala GMW90 - Manual (Page 55)

Chapter 4 _________________________________________________________________ Operation
VAISALA ________________________________________________________________________ 53
Calibration and Adjustment Commands
The following sections describe the calibration and adjustment
commands of the GMW90 series. For general information on performing
calibration and adjustment on the serial line, see section Adjustment
Using a Computer on page 68.
NOTE You must enable advanced serial commands using the PASS 9000
command before using the calibration and adjustment commands.
Adjust CO
2
Measurement
Use the CCO2 command to adjust the carbon dioxide (CO
2
)
measurement. You can do a 1-point or a 2-point adjustment, or clear the
adjustment information from the GM10 module. Note that the factory
adjustment will remain intact when user adjustment is cleared.
Remember to let the transmitter stabilize in the reference concentration
before entering the adjustment command. Three minutes is typically
enough.
NOTE Before using the CCO2 command, read section Notes for CO2
Adjustment on page 64.
Show Current CO
2
Adjustment
In addition to the user-adjustable offset and gain values, the CCO2
command displays diagnostic information that may be useful to Vaisala
Helpdesk if there is a problem with the adjustment.
CCO2
Example:
>pass 9000
>cco2
User gain : 1.000
User offset : -8.365
CO2 (pre-adjust) : 464.625
30s delta : 13.904
30s stddev : 4.429
Adjustability : CAN_ADJUST