Linear Heat Detector
This type comes in the form of length of wire or tube. Ideally suitable for cable tunnels, cable trays, transformer bays, etc. there are two types of linear.
heat detectors. One is theNon – Integratingtype consists of an electric cable with an insulation of fixed melting point which is suspended over the area to be protected. The melting of the insulation when there is a fire causes a short circuit which causes the system go into alarm mode. And the second type is theIntegrating type in which the insulation does not melt but electrical resistance is temperature dependent. The average temperature is taken over the whole length of wire rather than sections of it and change in resistance because of increase of temperature would sound the alarm.