High Specification Fire Detectors

Smoke detectors from the Discovery range may be ionisation, optical or multisensor types. It is generally accepted that ionisation types have a high sensitivity to fl aming fires whereas optical detectors have high sensitivity to smouldering fires. As a result of this, ionisation types are widely used for property protection, and optical types for life protection. These general principles still apply to the Discovery detectors, although the availability of a multisensor in the range offers more choice to the system designer. The multisensor is basically an optical smoke detector and will therefore respond well to the smoke from smouldering fires. In response modes 1, 3 and 4, however, (i.e., in the multisensor modes) the detector also senses air temperature. This temperature sensitivity allows the multisensor to give a response to fast burning (fl aming) fires, which is similar to that of an ionisation detector. The multisensor can therefore be used as an alternative to an ionisation detector while still retaining the benefits of an optical smoke detector. Where the environment is smoky or dirty under normal conditions, a heat detector may be more appropriate. It must be recognised, however, that any heat detector will respond only when the fire is well established and generating a high heat output.

	Drift compensation
	Sensitivity selection (see "applications" in technical info.)
	User programmable
	Conventional alarm on processor fault
	Rejection of transient signals

Discovery is a range of high-specification, intelligent fire detectors developed to meet the requirements of the sophisticated systems while providing engineers with an additional dimension in fire protection capability.

Discovery gives you total reassurance in installations where adaptability to changing conditions and protection against unwanted alarms are paramount. In addition to the familiar ionisation, optical and heat detectors, the Discovery range features a multisensor detector.

The process of designing a fire detection system using Discovery detectors is the same as that used for any other detector range, except that Discovery offers more choices to the system designer.

The principles set out in relevant codes of practice such as BS5839:Part 1 should be followed in any system design. These notes are intended to supplement the codes of practice and to give some specific guidance on the choices available with the Discovery range.

The choice of detector from the Discovery range follows the well established principles of system design. That is, the optimum detector type will depend on the type of fire risk and fire load, and the type of environment in which the detector is sited.

For general use, smoke detectors are recommended since these give the highest level of protection.