Operator`s manual

M2 Transmitter Operator’s Manual 6
The catalytic LEL detectors have a 1/2” NPT thread and require a 3/4”NPT x 1/2”NPT
reducer to install in the detector hub. The rest of the detectors have a 3/4” NPT mounting
thread and are installed directly in the detector hub.
The IR combustible detectors are generally used instead of the catalytic combustible
detectors in applications where there may be catalyst poisons such as silicone present or
where oxygen is not present in the monitoring environment.
Some of the detectors have a replaceable plug-in sensor. These detectors are described and
illustrated below.
There are four types of oxygen detectors available, a non-explosion proof partial pressure
type, a non-explosion proof capillary type, a non-explosion proof capillary type with a
replaceable sensor, and an explosion proof (CSA) capillary type with a replaceable sensor.
The capillary type’s output is less susceptible to variations in atmospheric pressure than
the partial pressure type. The CSA type oxygen detector (65-2514RK) and one of the non-
explosion proof capillary type detectors (65-2494RK) have a replaceable plug-in sensor
inside the detector housing while the entire oxygen detector must be removed if
replacement is required for the other two.
Figure 2: 65-2514RK Oxygen Detector, CSA
Flame Arrestor
Guard
Detector Housing Cap
Oxygen Sensor
Detector Housing Body
Cap Gasket