RKI Instruments Digester Gas Monitor - Manual (Page 34)

28 • Making Fitting Connections Digester Gas Monitor Operator’s Manual
6. Connect the leads from the recording device to the recorder output terminals of the
selected active channels as shown in Figure 16 below.
Figure 16: Recorder Output Wiring
Making Fitting Connections
Compression Fitting Connections
The fresh air inlet, dryer exhaust, digester sample inlet, and compressed air inlet fittings
are all compression fittings with ferrules that accept rigid metal or rigid plastic tubing. The
tube nuts are loosely screwed on and are not tightened completely. Do not tighten the tube
nut until a rigid tube is inserted.
The compression fittings accept 1/4 inch OD rigid metal or rigid plastic tubing. Stainless
steel, Teflon, or polypropylene tubing is recommended.
NOTE: Rigid metal must be used to connect to the compressed air inlet compression
fitting.
The maximum lengths of tubing that can be connected to each compression fitting, the
recommended size, and the recommended material are outlined in the table below.
Table 4: Compression Fitting Maximum Tubing Lengths
Fitting
Maximum
Tubing Length
(ft.)
Recommended Tubing Size
Recommended
Tubing Material
Fresh Air Inlet 100 • 1/4 inch OD x 3/16 inch ID plastic
• 1/4 inch OD x 0.035 inch wall metal
Stainless steel,
Teflon, or
polypropylene
Digester Sample
Inlet 100 • 1/4 inch OD x 3/16 inch ID plastic
• 1/4 inch OD x 0.035 inch wall metal
Stainless steel,
Teflon, or
polypropylene
Dryer Exhaust* 50 • 1/4 inch OD x 3/16 inch ID plastic
• 1/4 inch OD x 0.035 inch wall metal
Stainless steel,
Teflon, or
polypropylene
Recorder Output Terminals From a
Detector/Transmitter Terminal Strip,
Typical of 4
4-20 mA
OUTPUT
4 - 20 mA Input
Recording Device
500 Ohms Impedance
Maximum