SENSING APPARATUS AND METHOD

摘要

A method of detecting one or more blocked sampling holes in a pipe of an aspirated smoke detector system. The method includes ascertaining the base flow of fluid through a particle detector using a flow sensor; monitoring subsequent flow through the particle detector; comparing the subsequent flow with the base flow; and indicating a fault if the difference between the base flow and the subsequent flow exceeds a predetermined threshold.

主权项

1. An aspirated smoke detector comprising:
a particle detector, a sampling network including one or more pipes with one or more sampling holes through which samples enter the one or more pipes; and an aspirator for drawing an air sample through the sampling network to the particle detector; wherein the aspirated smoke detector includes an ultrasonic flow sensor arranged to detect the flow rate of air entering the particle detector.