18
October 2010
AUTOMATIKPRODUKTER
AUTOMATIKPRODUKTER
ATEX – Duct Smoke Detector
8
Product description
8.1
Design and mode of operation
of LRS 04 Ex
The Duct Smoke Detector LRS 04 Ex is preferably used in hazard areas classified
as zone 1 or 2. It detects both smoldering fires and open fires with development
of smoke at a very early stage. The Duct Smoke Detector utilises the scattered-
light principle. Inside the sensing chamber, a light source and a light sensor are
arranged such that the light beam of the light source cannot directly fall on the
light sensor. It is only when airborne particles enter the chamber that the light
scattered by these particles (Tyndall effect) reaches the sensor and is converted
into an electrical signal.
The figures below illustrate the structure and layout of the ventilation-duct
smoke switch system LRS 04 Ex:
Cable entry 1
Cable entry 2
Equipotential bond-
ing terminal, M6
Mounting holes
Ø 6 mm
Opening for tension-
ing strap
Fig. 8-01 Top view LRS 04 Ex
ORS 142 Ex interface
(connection box)
LKS 02
Inlet tube
Outlet tube
Fig. 8-02 Side view LRS 04 Ex
1
4
5
2
3
6
7
9
8
