6 • 65-2424RK H
2
S Transmitter
Description
This section describes the components of the H
2
S transmitter. The transmitter consists of the
H
2
S sensor, sealing spacer, amplifier printed circuit board (PCB), and enclosure.
Figure 1: H
2
S Transmitter Component Location
H
2
S Sensor
The sensor is cylindrical with the sensing face on the top and the connection pins on the
bottom. The sensor plugs into the amplifier PCB with the four pins. The sensor is exposed to
the ambient air through an opening in the enclosure cover. Through a series of chemical and
electrical reactions, the sensor produces an electrical output that is proportional to the
detection range of the transmitter.
Sealing Spacer
The ring shaped plastic sealing spacer fills a gap in the rubber boot that is installed on the
sensor. The rubber boot is used to seal the sensor to the enclosure cover in both the CO and
H
2
S transmitters. In the CO transmitter the rubber boot also retains a charcoal filter. Since a
charcoal filter is not used in the H
2
S transmitter, the sealing spacer fills the space that would
be filled by the charcoal filter’s body.
ZERO
R
CAL-
CAL+
+V
FB
B
SPAN
Sensor (w/sealing
spacer & boot)
Enclosure
(shown w/out cover)
Interconnect
Terminal Strip
Amplifier PCB
Zero Pot
Span Pot
Test Point CAL-
Factory Set Pot
Amplifier PCB Mounting
Screw (under sensor)
Cable Bushing
Amplifier PCB
Mounting Screw
Test Point
CAL+
