RKI Instruments 65-2394RK - Manual (Page 6)

2 • 65-2394RK Combustible Gas Transmitter
Description
The 65-2394RK combustible gas transmitter has two versions, the 65-2394RK-CH4 which
is calibrated to methane and the 65-2394RK-HC which is calibrated to propane. The
transmitter utilizes an infrared type of detector which has some advantages over a
catalytic type of combustible detector. The infrared detector will generally have a longer
service life than a catalytic detector, it will require calibration less often, and it can detect
combustible gas even if there is no oxygen in the sample which allows detection of
combustible gas in an inert atmosphere.
This section describes the components of the combustible gas transmitter. The transmitter
is a 4 - 20 mA type detector head. It consists of the combustible gas detector, amplifier, and
junction box.
Figure 1: Combustible Gas Transmitter Component Location
Infrared LEL Detector
The infrared LEL detector is made up of a miniature infrared combustible gas LEL
detector housed and encapsulated in a pipe nipple. The pipe nipple has 3/4” NPT threads
on each end and a 1 1/4” hex that allows removal or installation of the detector with a
G
W
RB
LE
L
5
7
-1
053
R
K
PW
R
/
S
IG
S
S
2
0
0
1
Amplifier
Controller Terminal
Strip
Detector Terminal
Strip
IR LEL Detector
J-Box
Se
n
so
r
Cu
rr
e
n
t
m
A
SP
A
N
Jumper Pins,
Factory Use
Only
Factory Adjust
Pot
Zero Pot
Span Pot
Factory Adjust Pot
ZE
R
O
+ Test Point
- Test Point