RKI Instruments Digester Gas Monitor - Manual (Page 23)

Digester Gas Monitor Operator’s Manual Internal Description • 17
appropriate flow rate depends on the full scale range of the H
2
S sensor. See “Adjusting
the Flow Rates” on page 33 for more information.
H
2
S Dilution Air Flowmeter
The H
2
S Dilution Air flowmeter is located in the middle right of the Digester Gas Monitor’s
flow system and indicates the fresh air flow rate to the H
2
S sensor. The appropriate flow
rate depends on the full scale range of the H
2
S sensor. See “Adjusting the Flow Rates” on
page 33 for more information.
Hydrophobic Filter
The hydrophobic filter is located in the upper left corner of the Digester Gas Monitor
housing and prevents water from entering the flow system through the sample inlet that
may have gotten past the water trap.
Water Trap
The water trap is located in the upper left corner of the Digester Gas Monitor housing. It is
slightly below and to the right of the hydrophobic filter. The water trap prevents water from
entering the flow system through the sample inlet. During the blowback procedure, the
water trap is emptied of its contents.
Dryer
The dryer is located in the center of the Digester Gas Monitor and removes any excess
humidity in the sample before the sample enters the flow chamber.
Solenoid Valves
There are five solenoid valves located throughout the Digester Gas Monitor’s flow system.
They control the direction of the flow. They are controlled by the Digester Gas Monitor’s
software and are actuated at various stages of the sampling process.
Check Valves
A check valve in the blowback exhaust line prevents fresh air from entering the sample
line through the blowback exhaust line.