6 • 65-2396RK CO
2
Transmitter
Description
This section describes the components of the CO
2
transmitter. The transmitter is a 4 - 20 mA type
detector head. It consists of the CO
2
detector, amplifier, and junction box.
Figure 1: CO
2
Transmitter Component Location
Infrared CO
2
Detector
The CO
2
detector is made up of a miniature infrared CO
2
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 wrench. A porous flame arrestor that is coated with a hydrophobic
film that repels liquids is on one end of the detector and allows sample gas to enter the detector. Four
color coded leads, red, white, green, and black, extend from the other end of the detector. The leads
allow you to connect the detector to the amplifier.
To distinguish the different ranges of CO
2
detectors from one another, a short length of shrink tubing is
applied to the wiring where it comes out of the nipple. The following table indicates the color of the
shrink tubing and the color of the wire to which it is applied.
Amplifier
Controller Terminal
Strip
W
RB
5
7
-1
05
3R
K
S
2
0
0
1
G
Detector Terminal Strip
J-Box
IR CO2 Detector
Se
n
s
o
r
Cu
rr
e
n
t
m
A
Factory Adjust Pot
Zero Pot
Span Pot
Factory Adjust Pot
Jumper Pins,
Factory Use Only
SP
A
N
ZE
R
O
- Test Point
+ Test Point
S
LE
L
PW
R
/
SI
G
