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65-2645-05SS-04 M2A Transmitter Operator’s Manual
Detector Housing Body
The detector housing body protects the electronic components within the housing. Use the mounting threads at
the top of the housing to screw the H
2
S detector into the 3/4 NPT hub on the bottom of the detector junction box.
Two wires extend from the top of the detector housing body. Use these wires to connect the H
2
S detector to the
terminal strip. One of the wires is red and one of the wires is black.
The housing includes a four-socket pattern. This socket pattern accepts the sensor’s four pins to secure the sensor
within the detector housing. A pre-amplifier, located between the sockets and two interconnect wires, conditions
the sensor’s signal before the signal reaches the controller.
Housing Cap & Cap Gasket
The housing cap screws onto the detector housing. It retains the plug-in sensor and protects it from damage. The
housing cap also includes a flame arrestor which contains any sparks that may occur within the detector and a
flame arrestor guard which protects the flame arrestor from damage. Unscrew the detector cap to access the plug-
in sensor for maintenance or replacement. A cap gasket seals the interface between the housing and cap. A flame
arrestor guard is permanently bonded to the cap.
Rubber Boot and Spacer
A rubber boot and spacer are installed between the detector housing cap and the sensor. They help ensure that the
sensor remains plugged into the detector housing body.
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.
Calibration Adapter/Splash Guard
A calibration adapter/splash guard is installed on the H
2
S detector. A fitting at the bottom of the calibration
adapter/splash guard allows a length of tubing to be connected for calibration and routed to a more easily
accessible location (near the M2A junction box is optimal for ease of calibration). The calibration adapter/splash
guard also protects the detector from splashing water or direct water spray.
Magnetic Wand
The magnetic wand is a short plastic rod with a magnet in one end. It is used to actuate the magnetic control
switches on the control PCB while the junction box cover is still installed so that non-intrusive calibration can be
performed.
