65-2340RK Toxic Gas Transmitter • 9
Span Pot
The span pot is located to the right of the zero pot (see Figure 3). 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
span output and counterclockwise to decrease the span output.
CAUTION:
The amplifier includes an additional potentiometer. It is factory-set. Do not adjust
it.
Test Points
The test points are on the left side of the amplifier (see Figure 3). The test points produce a
100 mV 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 amplifier’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.
Junction Box
Use the junction box to install the transmitter at a mounting site that is remote from the
controller. The junction box protects the amplifier and wiring connections made to the
amplifier. Use the top 3/4 NPT conduit hub to connect wiring from the amplifier to the
controller. Use the cover on the front of the junction box to access the interior of the junction
box. The detector and amplifier are factory installed in the junction box. Three spacers
installed on the back of the junction box control the distance of the junction box from a
mounting surface and ensure that there is enough room to install a calibration cup on the
detector during calibration.
Installation
This section describes procedures to mount the toxic gas transmitter in the monitoring
environment and wire the transmitter to a controller.
Mounting the Toxic Gas Transmitter
1. Select a mounting site that is representative of the monitoring environment. Consider the
following when you select the mounting site.
•
Select a site where the transmitter is not likely to be bumped or disturbed. Make sure
there is sufficient room to perform start-up, maintenance, and calibration procedures.
•
Select a site where the target gas is likely to be found first.
