Flame Detection, Photoelectric cells detect the emission of infra‐red /ultra-violet radiation.
Flammable Gas Detection, Flammable gas detectors measure the amount of flammable gas in the atmosphere and compare the value with a reference value. When this is exceeded the gas supply valve is closed an alarm is actuated.
Heat Detection, Heat detection can be used as a means of actuating a mechanical control or sprinkler system. The disadvantage of heat detection is that toxic smoke can be evolved from burning materials long before sufficient heat is generated to trigger the mechanism. These systems are rarely relied upon as a means of raising the alarm, however where fires raise little smoke, e.g. solvent fires, fixed temperature or rate of rise detectors can be used.
Fusible links are sensors operated by the melting of a metal (fusion detectors), e.g. used to open automatic smoke vents and close ventilation system dampers and shutters; or expansion of a solid, liquid or gas (thermal expansion detectors), e.g. to actuate sprinkler systems.
Flammable Gas Detection, Flammable gas detectors measure the amount of flammable gas in the atmosphere and compare the value with a reference value. When this is exceeded the gas supply valve is closed an alarm is actuated.
Heat Detection, Heat detection can be used as a means of actuating a mechanical control or sprinkler system. The disadvantage of heat detection is that toxic smoke can be evolved from burning materials long before sufficient heat is generated to trigger the mechanism. These systems are rarely relied upon as a means of raising the alarm, however where fires raise little smoke, e.g. solvent fires, fixed temperature or rate of rise detectors can be used.
Fusible links are sensors operated by the melting of a metal (fusion detectors), e.g. used to open automatic smoke vents and close ventilation system dampers and shutters; or expansion of a solid, liquid or gas (thermal expansion detectors), e.g. to actuate sprinkler systems.
Figure: Thermal Expansion, Fusible Solder Link Sprinkler Head
Figure: Thermal Expansion, Quartzoid Bulb Sprinkler Head
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