RKI Instruments 65-2451RK - Manual (Page 6)

2 • 65-2451RK Hydrogen Transmitter
Description
This section describes the components of the hydrogen transmitter. The transmitter is a 4 -
20 mA type detector head. It consists of the hydrogen detector, amplifier, and junction
box.
Figure 1: Hydrogen Transmitter Component Location
Hydrogen Detector
The hydrogen detector is a catalytic type detector that produces an electrical output that
corresponds to the detection range. It is packaged in a 1/2 inch NPT nipple with a sintered
metal flame arrestor on one end allowing ambient air to diffuse into the detector. The
flame arrestor also contains any sparks which may occur within the detector. The detector
has a built in molecular sieve that only allows hydrogen to diffuse into the detector. The
1/2 inch NPT mounting threads at the top of the detector allow you to mount it into the
bottom conduit hub of the junction box. A rainshield screws onto the bottom of the
detector (flame arrestor end). The rainshield helps protect the detector from rain and
debris in the monitoring environment. Four color-coded leads extend from the top of the
detector. The leads allow you to connect the detector to the amplifier.
B
LE
L
Controller Terminal Strip
Amplifier
Mounting Screw
S
G
W
R
PW
R
/ S
IG
Detector (sensor) Current
Label
J-Box
Detector Terminal Strip
Zero Pot
Span Pot
Factory Adjust Pot
Factory Adjust Pot
Jumper Pins,
Factory Use Only
Red + Test Point
Hydrogen
Detector
Se
n
so
r
Cu
rr
e
nt
m
A
Reducing Bushing,
3/4 NPT to 1/2 NPT
Black - Test Point
SP
A
N
ZE
R
O