Performing a calibration – RKI Instruments Digester Gas Monitor User Manual
Page 69
Digester Gas Monitor Operator’s Manual
Performing a Calibration • 63
2.
With SET CAL TIMEOUT displayed, press and release the ENTER button. The
Calibration Timeout Screen appears.
3.
Use the UP/YES or DOWN/NO button to adjust the calibration timeout to the desired
setting. The calibration timeout can be set from 5 minutes to 240 minutes (4 hours) in
5 minute increments. The factory set calibration timeout is 15 minutes.
4.
If you want to save the displayed calibration timeout setting, press and release the
ENTER button. The display will indicate that the setting has been saved before
returning to the Select Operation Screen.
If you do not want to save the displayed calibration timeout setting, press and release
the ESCAPE button. The display will indicate that nothing has changed before
returning to the Select Operation Screen.
5.
Press and release the ESCAPE button.The You Have Entered The CALIBRATION
Mode... message displays and asks if you want to continue in Calibration Mode.
6.
Press the DOWN/NO button to exit Calibration Mode and enter Standby Mode.
Performing a Calibration
It is possible to perform only an air adjustment or a gas response adjustment since it is not
always necessary to perform a complete calibration. For example, during startup, it is
typically only necessary to perform an air adjustment since the Digester Gas Monitor is
shipped with all the factory setup channels calibrated. However, for a complete calibration,
you must perform both a fresh air adjustment and a gas response adjustment.
The H
2
S channel (typically channel 4) must always be calibrated separately from the other
channels. The methane, oxygen, and CO
2
channels (typically channels 1-3) may be
calibrated together or separately. This means that the fresh air adjustment procedure and
the gas adjustment procedure must each be completed at least twice in order to perform a
complete calibration.
To perform a calibration, you will need:
•
known calibrating samples of the gases being detected
•
a demand flow regulator
•
non-absorbent tubing
WARNING:
Before performing a calibration, confirm that the tubing coming from the
aspirator/sample exhaust barb fitting is routed to an area where it can be safely
discharged.
Calibration Timeout
15 minutes
UP / DN then ENT / ESC