RKI Instruments Pioneer 4W - Manual (Page 106)

Pioneer Operator’s Manual CO Transmitter • 3
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.
Filter
The disc-shaped filter is secured to one end of the sensor. The filter prevents interference
gases (hydrogen sulfide [H
2
S] and certain hydrocarbons) from producing false CO
readings. The filter is held in place by a rubber boot.
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 the Pioneer. The amplifier
includes the amplifier type selector, detector terminal strip, interconnect terminal strip,
span potentiometer, zero potentiometer, test points, and sensor backup battery
(see Figure 1.)
Amplifier type selector
The amplifier type selector is near the top left corner of the amplifier. It is above the
detector terminal strip and to the left of the span potentiometer.
The amplifier included with the CO 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 CO 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 on the left side of the amplifier.
Use the detector terminal strip to connect the CO detector to the amplifier.
NOTE: The CO detector is factory-wired to the amplifier. See the Installation section of
this insert for all wiring procedures related to the transmitter.
Interconnect terminal strip
The interconnect terminal strip is the four-point terminal strip on the right side of the
amplifier. Use the interconnect terminal strip to connect the amplifier to the Pioneer.
Span potentiometer
The span potentiometer is near the top of the amplifier. Of the three potentiometers, the
span potentiometer is farthest to the left. Use the span potentiometer to adjust the
transmitter’s response output during the calibration procedure.
Zero potentiometer
The zero potentiometer is to the right of the span potentiometer. Use the zero
potentiometer 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.