Application for flame detectors, Quantities required and positioning of detectors – Hochiki IFD-E User Manual

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Hochiki Europe (UK) Ltd



Application for Flame Detectors

Flame detectors are used when detection is required to be:

Unaffected by convection currents, draughts or wind

Tolerant of fumes, vapours, dust and mist

Responsive to a flame more than 25m away

Fast reacting

The detector is capable of detecting the optical radiation emitted by burning material even non-
carbonaceous materials. e.g. Hydrogen

Numerous other potential fire sources can be detected such as:




● Aviation Fuels (kerosene)


● Butane


● Cotton

● Fluorine

● Methylated Spirits

● Grain & Feeds

● Hydrogen

● n-Heptane


● Natural Gas


● Refuse

● Off Gas

● Petrol (gasoline)


● Propane

Typical applications examples are:

● Agriculture

● Coal handling plant

● Pharmaceutical

● Aircraft hangars

● Engine rooms

● Power plants


● Generator rooms

● Textiles

● Automotive industry

● Metal fabrication

● Transformer stations

- spray booths

● Paper manufacture

● Waste handling

- parts manufacture

● Petrochemical

● Woodworking

Applications and Locations to Avoid:

● ambient temperatures above 55°C

● large IR sources – heaters, burners, flares

● close proximity to RF sources

● obstructions to field of view

● exposure to severe rain and ice

● sunlight falling directly on the detector optics

● large amounts of flickering reflections ● spot lighting directly on the detector optics

Quantities Required and Positioning of Detectors

The number of detectors required and their position depends on:

the anticipated size of the flame

the distance of the flame from the detector

the angle of view of the flame detector

The flame detector is designed to have a class 1 performance as defined in BS EN54-10:2002 on the
high sensitivity setting. That is the ability to detect an n-heptane (yellow) fire of 0.1m² or methylated spirit
(clear) fire of 0.25m² at a distance of up to 25m within 30 seconds.

The detector can be set to have to a lower sensitivity setting equivalent to class 3 performance. Class 3
performance is defined as detecting the same size fires as for class 1 but at a distance of only 12m.