Patent ID: 6700496
Filing Date: 2004-03-02
Classification: G08B

Abstract:
A flame detector for detecting the presence of a flame or spark in front of the detector, comprising:a UV sensitive photocathode and an anode, wherein the UV sensitive photocathode is oriented such that UV-light from a flame or spark present in front of the detector can strike the UV sensitive photocathode; a voltage supply unit connected to the UV sensitive photocathode and to the anode to create an electric field such that photoelectrons emitted from the UV sensitive photocathode, when struck by UV-light from a flame or spark present in front of the detector, are forced to move towards the anode; a readout arrangement adapted to detect charges induced by electrons moving towards the anode and which are indicative of the presence of a flame or spark in front of the detector; and a chamber filled with a gas and arranged such that photoelectrons emitted from the UV sensitive photocathode can interact with the gas when moving towards the anode, wherein the detector is adapted to avalanche multiply photoelectrons emitted from the UV sensitive photocathode.