RKI Instruments 65-2331RK - Manual (Page 8)

4 • 65-2331RK H
2
S Transmitter
Plug-In H
2
S Sensor
The sensor is secured within the detector assembly by the housing cap. Through a series
of chemical and electrical reactions, the sensor produces an electrical output that
corresponds to the detection range of the transmitter.
Amplifier
The amplifier converts the electrical output from the sensor to a 4 to 20 mA signal that
corresponds to the detection range and transmits the signal to a gas monitoring controller.
A foam gasket that orients the amplifier and keeps it from rotating is installed on the
bottom of the amplifier. The amplifier includes the controller terminal strip, detector
terminal strip, zero pot, span pot, and test points (Figure 1).
Controller Terminal Strip
The interconnect terminal strip is a two position plug-in style terminal strip located at the
top edge of the amplifier. Use the controller terminal strip to connect the amplifier to a
controller.
Detector Terminal Strip
The detector terminal strip is a four-point plug-in style 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 detector terminal strip. See the
Installation section of this manual for all wiring procedures related to the
transmitter.
Zero Pot
The zero pot is located in the upper left corner of the amplifier (see Figure 1). Use a small
flat blade screwdriver to turn the zero pot’s adjustment screw and adjust the amplifier’s
zero (H
2
S free) output during the start-up and calibration procedures. Turn the
adjustment screw clockwise to increase the zero output and counterclockwise to decrease
the zero output.
Span Pot
The span pot is located to the right of the zero pot (see Figure 1). Use a small flat blade
screwdriver to turn the span pot’s adjustment screw and adjust the amplifier’s response
output during the calibration procedure. Turn the adjustment screw clockwise to increase
the output and counterclockwise to decrease the output.
CAUTION: The third potentiometer is factory-set. Do not adjust it.
Test Points
The test points (red and black) are on the left side of the amplifier (see Figure 1). The test
points produce a 100mV to 500 mV output that corresponds to the transmitter’s 4 to 20
mA output. Use the test points and a voltmeter to measure the transmitter’s output
during the start-up and calibration procedures. The black test point in the lower left
corner is the negative (-) test point and the red test point below the zero pot is the positive
(+) test point.