9
1.1 Intrinsically safe toxic and oxygen gas detector
This version of
Xgard
is an Intrinsically safe looppowered (currentsink)
420 mA toxic or oxygen gas detector, designed to detect a wide range
of gases when fitted with the appropriate electrochemical sensor. The
detector is certified
II 1 G EEx ia IIC T4, and is suitable for use in
Zone 0, Zone 1 and Zone 2 hazardous areas when used with a suitable
Zener barrier or galvanic isolator.
Electrical connections to the detector are made via the terminal block on
the amplifier PCB shown below. The amplifier provides power to the
sensor, and converts the sensor signal into a 420 mA signal for
connection to a control panel.
Diagram 4:
Xgard
Type 1 PCB layout
(Shown with PCB cover removed).
1. Introduction
Xgard Type 1
Internal
grounding
terminal
(earth)
Test
points
Set zero
Run
Links for Crowcon
use (toxic version
only)
Supple
mental
external
grounding
terminal
(earth)
