Teledyne 1220 - Multipoint flammable gas and vapor detection system - Manual (Page 10)

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1 Introduction Model 1220
Teledyne Analytical Instruments
• Failure codes and testpoints
• Two selectable analog outputs (0-10VDC or negative ground
4-20mADC)
• Extensive, automatic self-test diagnostic testing during operation
• Compact and versatile design: Small footprint with accessible
internal PCBs
1.2.4 Detector
The detector is a low temperature, catalytic oxidation, diffusion type
sensor. Each detector contains two beads: a catalytically active bead and a
thermally identical inert bead. Each bead is integrated onto a platinum
heating coil and is mounted on a stainless steel support bar. With this
rugged mounting system the detector is extremely vibration and shock
resistant. The detectors are installed near the potential source of leaks in
the region expected to be first exposed to the gas.
Combustible Gas Detector
1.2.5 Terminal Strip Housing
The terminal strip housing and probe mounts provided for this system
are junction boxes having two hubs with 3/4” pipe treads. The sensor
screws into one hub and the other hub will accommodate standard conduit.
A three-point terminal strip is installed within the housing for connec-
tion of the probe.