ADDRESSABILITY IN PARTICLE DETECTION

A smoke detection system comprising: a particle detector having an ordinary detection mode; a particle detector having a high speed detection mode; an aspirator; an air sampling network having: at least one sampling pipe with a plurality of sampling inlets through which smoke can enter the air sampling network; a fan and a valve at a distal end to the or each detector; a mechanism for delivering purging air to the air sampling network; and a mechanism for controlling the valve and the fan, the smoke detection system being configured to: operate in a detection mode in which the aspirator draws air through the sampling inlets along the sampling pipe to the particle detector having an ordinary detection mode for analysis; operate in a purge mode to purge the air sampling network of particle laden air and displace it with clean air; and operate in a localisation mode in which the particle detector having a high speed detection mode operates in a high speed detection mode which smoke detection response is faster than the ordinary detection mode, to determine which of the plurality of sampling inlets smoke has entered the air sampling system. A method is also provided.