8 • 65-2422RK-05 H
2
S Transmitter
Plug-In H
2
S Sensor
The sensor is secured within the sensor housing by the four pins. Through a series of chemical
and electrical reactions, the sensor produces an electrical output that is proportional to the
detector range of the transmitter.
Amplifier
The amplifier converts the electrical output from the sensor to a 4 to 20 mA signal (that is
proportional to the detection range) and transmits the signal to a gas monitoring controller.
The amplifier includes the amplifier type selector, detector terminal strip, interconnect
terminal strip, span pot, zero pot, and test points (see Figure 1).
Amplifier Type Selector
The amplifier type selector is near the bottom left corner of the amplifier. It is to the left of the
detector terminal strip and below the span potentiometer.
The amplifier included with the H
2
S transmitter is designed for use with RKI’s toxic gas and
oxygen transmitters. The amplifier type selector determines for which transmitter the
amplifier is intended. For H
2
S transmitters, a jumper block is installed over the
TOXIC
selector (see Figure 1).
Detector Terminal Strip
The detector terminal strip is the four-point terminal strip near the bottom of the amplifier.
Use the detector terminal strip to connect the H
2
S detector to the amplifier.
NOTE:
The H
2
S detector is factory-wired to the amplifier. See the Installation section of this
manual for all wiring procedures related to the transmitter.
Interconnect Terminal Strip
The interconnect terminal strip is the four-point terminal strip near the top of the amplifier.
Use the interconnect terminal strip to connect the amplifier to a controller.
Span Pot
The span pot is on the left side of the amplifier. Of the three potentiometers, the span pot is
bottom most. Use the span pot to adjust the transmitter’s response output during the
calibration procedure.
Zero Pot
The zero pot is above the span pot. Use the zero pot to adjust the transmitter’s target gas-free
output during the start-up and calibration procedures.
CAUTION:
The third potentiometer is factory-set. Do not adjust it.
