8 • 65-2443SS PPM Hydrogen Transmitter
Test Points
The test points are on the right side of the amplifier (see Figure 2). The test points produce a 100 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
on the bottom is the negative (-) test point and the red test point on the top is the positive (+) test point.
Junction Box
The stainless steel, corrosion resistant junction box allows you to install the detector at a mounting site
that is remote from a controller, and it protects the detector wiring connections. Two conduit hubs
allow you to mount the detector to the junction box and connect the wiring from the detector to a
controller. An O-ring seals the interface between the junction box cover and the junction box base.
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. A locking set screw on the junction box cover
allows you to secure the junction box cover and prevent it from being removed.