دتکتور گاز Crowcon Xgard Type 4

detector part number : S011954

Pellistor Type: VQ21T

Introduction
Flameproof high temperature flammable gas detector
This version of Xgard is a Flameproof high temperature (150°C / 302°F) gas detector, designed to detect flammable gas present in ambient air, at concentrations not exceeding the Lower Explosive Limit (LEL) of the target gas for which it is calibrated. Xgard Type 4 operates using pellistors as part of a 3-wire Wheatstone Bridge (WB) circuit, and must be connected to a suitable control card. The detector is certified II 2 GD Ex db IIC T3 Gb, and is suitable for use in Zone 1 and Zone 2 hazardous areas. Electrical connections to the detector are made via the terminal block on the PCB shown below.