RKI Instruments 65-2396RK - Manual (Page 7)

65-2396RK CO
2
Transmitter • 3
To distinguish the different ranges of CO
2
detectors from one another, a short length of
shrink tubing is applied to the wiring where it comes out of the nipple. The following
table indicates the color of the shrink tubing and the color of the wire to which it is
applied.
Amplifier
The amplifier converts the electrical output from the detector 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 detector terminal strip, controller
terminal strip, span pot, zero pot, and test points (see Figure 1).
Controller Terminal Strip
The controller terminal strip is a three position plug-in style terminal strip located near the
top of the amplifier. Use the controller terminal strip to wire the CO
2
transmitter to a
controller.
Detector Terminal Strip
The detector terminal strip is a four position plug-in style terminal strip located below the
controller terminal strip. Use the detector terminal strip to connect the CO
2
detector to the
amplifier.
NOTE: The IR CO
2
detector is factory-wired to the detector terminal strip. See “Wiring
the CO
2
Transmitter to a Controller” on page 5 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
target gas-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 gas
response output during the calibration procedure. Turn the adjustment screw clockwise to
increase the gas response and counterclockwise to decrease the gas response.
Table 2: CO
2
Detector Color Designations
Detector Color Designations
0 - 5,000 ppm black shrink tubing on white wire
0 - 5% volume green shrink tubing on white wire
0 - 50% volume green shrink tubing on red wire
0 - 100% volume red shrink tubing on green wire