4 SENSOR SAFETY DESCRIPTION
4.1 HAZARDOUS ZONES
The sensor may be installed in a metal stack or duct containing hazardous dust, but the control unit must be installed
in the designated Safe Area (see the Functional Diagram below). The control unit contains the power supply, alarm
connections, and user controls. The sensor unit is mounted to the ductwork such that the metal probe rod protrudes
into the flow of the particulate to be monitored.
4.1.1 Hazardous Zone Classification
The instrument is suitable for use in the following Ex zones:
Gas zone
Dust zone
4.1.2 Functional Diagram
Figure 3: Hazardous zone layout (zones 2 and 22)
WARNING!
The X22 sensor does not have an energy limiter fitted and must NOT be used in zones 20 and 21!
INSTALLATION AND OPERATION MANUAL – OWNER'S RECORD FFA MANUAL – FILTER FAILURE ALARM
INSIDE STACK
OUTSIDE STACK
Zone 2
Zone 2
Zone 22
Zone 22
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