RKI Instruments Digester Gas Monitor - Manual (Page 43)

Digester Gas Monitor Operator’s Manual Normal Operation • 37
5. The H
2
S reading is taken after 90 seconds. The solenoids will click and the flow to the
sensors will be stopped for 15 seconds to allow for a stabilization period. The
countdown will continue on the display.
6. At the end of the stabilization period, the methane, oxygen, and carbon dioxide
readings will be taken. The gas readings for all channels will then be displayed for 5
seconds.
7. A 60 second post-sample purge will then be performed to clear the Digester Gas
Monitor of any residual sample.
8. A 10 second blowback period follows the post-sample purge. The blowback clears the
hydrophobic filter and the water trap of any contaminants.
9. Once the blow back operation is complete, the Digester Gas Monitor will return to
Standby Mode. The gas readings displayed will be the last recorded gas readings at
the end of the sample period described in step 4.
10. The detection cycle will occur again in a time period defined by the Cycle Interval Time
in the Global Menu.
Sampling
0 Min 14 Seconds
1: METHANE 34 %LEL
2: OXYGEN 0.9 %VOL
3: CO2 15.3 %VOL
4: H2S 678 ppm
Fresh Air Purge
0 Min 59 Seconds
Blow Back
0 Min 9 Seconds
Standby Mode
# of Samples 0
Next Detection Cycle
in 0D: 0H: 59M: 59S 1: METHANE 0 %VOL
2: OXYGEN 20.9 %VOL
3: CO2 0.0 %VOL
4: H2S 0 ppm