Principle of Operation

Emergency Warning Systems - Principle of Operation

For many of us, the first time we learn about an emergency, is when we hear the telltale signs of an emergency warning system in operation.

A emergency warning system is a life safety system installed to safeguard occupants from illness or injury by warning them of a fire or emergency and to safeguard occupants during the orderly evacuation of a building in an emergency. They assist in these two functions by;

  • providing mass notification of an emergency; and
  • providing a method to communicate with and direct building occupants in the event of an emergency.

Portable Fire Extinguishers - Principle of Operation

A portable fire extinguisher by definition is an item of equipment for the purpose of extinguishing a fire. The reality is however that a portable fire extinguisher is effective only for the type and size of a fire that it is rated for.

Portable fire extinguishers are generally provided as "first attack" units in fire fighting and should be used only in early stages of fire before the fire grows to a stage that is beyond the capacity of the extinguisher. There are broadly six types of fire extinguisher; Water, Foam, Wet Chemical, Dry Chemical Powder, Vaporising Liquid and Carbon Dioxide. The selection of an extinguisher must be made with the class of fire in mind.

Fire Hydrant Systems - Principle of Operation

In a building, a fire hydrant system is a safety measure or emergency equipment required in some buildings that comprises a series of components that when assembled together provide a source of water to assist fire authorities in a fire.

Putting it another way, a fire hydrant system is a water supply with a sufficient pressure and flow delivered through pipes throughout a building to strategically located network of valves for fire-fighting purposes.

Heat Detectors - Principle of Operation

The third instalment of the Principle of Fire Safety series looks at heat detectors, one of the four methods of detecting fire through the the by-products of combustion. This is an area of fire safety that has been rapidly evolving over the last 20 years.

Research and development has improved well established detection technologies and provided an array of new technologies to improve fire detection while also being less susceptible to the causes of false alarms.

Before we go any further it's important to lay the foundation for what is fire; fire also known as combustion is a sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the by-products of combustion being; heat, smoke & electromagnetic radiation (light). Personally I think a illustration explains this chemical reaction in terms easier to understand.

It is also important to recognise that smoke is an aerosol or mixture of particulates suspended in air that comprises a collection of airborne solids, liquid particulates and gases emitted when a material undergoes combustion.

This is important because each of the four detection technologies are designed to respond to one of the three by-products of combustion. There are four principal methods for detecting fire explored in this article including; Heat, Smoke, Flame and Combustion detectors.

Fire Alarm Systems - Principle of Operation

Rarely in the movies do you ever see a Fire Indicator Panel (FIP), more often than not you will see an American style 'pull station' - the equivalent of a Manual Call Point or Break Glass Alarm found in Australia.

A Fire Indicator Panel (FIP) is probably best described as the 'brains' of a fire detection and alarm system. A fire indicator panel comprises control and indicating equipment (c.i.e) that combined together form an integrated system. These core components comprise;