CALL POINTS
The Manual Call Point, the Human Fire Detection System Mark Thomson KAC Alarm Company
INTERNATIONAL FIRE PROTECTION
Even in the most sophisticated fire system installed in the most modern of premises, call points perform a vital role in enabling anyone to raise the alarm in the event of discovering a fire.
T
he activation of a fire detection system is achieved either automatically, initiated by a detector, or through a manual call point or pull station. Call points are used throughout Europe, Australasia and the Far East and pull stations are predominantly to be found in North America. Although the manual devices are very different in their design and operation, they are both the only Human Machine Interface (HMI) mechanism that an occupant of a building can use to activate the fire alarm system. In certain circumstances, human intervention is going to be the fastest way of raising the alarm. For example, consider a boiler room, which typically will be protected by a thermal detector. If a slow
smouldering fire was to develop, the thermal detector would take a very long time to respond, whereas someone entering the room will be able to react to the situation immediately.
The History Long before the development of smoke detectors in 1941, the break-glass call point was the only means of activating the simple fire systems of the time. Today’s intelligent automatic fire detection systems are complex arrangements of sophisticated detectors, high performance audible and visible warning devices and automated controllers for external systems such as air-conditioning systems, door controllers and other equipment, all managed 39