Detector assembly
First Claim
1. A detector assembly for detecting vapours, said detector assembly comprising:
- a detector unit comprising a UV sensitive photocathode and an anode;
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 are forced to move towards the anode;
a readout arrangement for detecting charges induced by electrons moving towards the anode thereby generating a signal related to the intensity of detected UV light, wherein an artificial source for emitting radiation having wavelengths within a wavelength interval, the source being oriented such that UV light from the source can strike the UV sensitive photocathode;
said wavelength interval coinciding with a transmission band of air, and said wavelength interval further coinciding with an absorption band of vapours containing molecules of a complex structure; and
that said readout arrangement is arranged to detect a decrease of said signal between the detector and the source, whereby a presence of a vapour can be established.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention is related to a detector assembly for detecting vapours, smoke and flames, comprising a detector unit 1 having a UV sensitive photocathode 3, an anode 5, a voltage supply unit 9 connected to the UV sensitive photocathode 3 and to the anode 5 to create an electric field such that photoelectrons emitted from the UV sensitive photocathode 3, when struck by UV light, are forced to move towards the anode 5, and a readout arrangement for detecting charges induced by electrons moving towards the anode 5 thereby generating a signal related to the intensity of detected UV light. The detector assembly further comprises an artificial source 21 for emitting radiation having wavelengths within a wavelength interval, the source 21 being oriented such that UV light from the source 21 can strike the UV sensitive photocathode 3. The wavelength interval coincides with a transmission band of air, and with an absorption band of vapours containing molecules of a complex structure. If a decrease of the signal between the detector 1 and the source 21 is detected a presence of a vapour can be established. The invention is also related to such a method.
11 Citations
34 Claims
-
1. A detector assembly for detecting vapours, said detector assembly comprising:
-
a detector unit comprising a UV sensitive photocathode and an anode;
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 are forced to move towards the anode;
a readout arrangement for detecting charges induced by electrons moving towards the anode thereby generating a signal related to the intensity of detected UV light, wherein an artificial source for emitting radiation having wavelengths within a wavelength interval, the source being oriented such that UV light from the source can strike the UV sensitive photocathode;
said wavelength interval coinciding with a transmission band of air, and said wavelength interval further coinciding with an absorption band of vapours containing molecules of a complex structure; and
that said readout arrangement is arranged to detect a decrease of said signal between the detector and the source, whereby a presence of a vapour can be established. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
-
-
23. A method for detecting vapours by utilising a detector unit comprising a UV sensitive photocathode and an anode, 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 are forced to move towards the anode, and a readout arrangement for detecting charges induced by electrons moving towards the anode thereby generating a signal related to the intensity of detected UV light, said method comprising the steps of:
-
emitting, at an artificial source, radiation having wavelengths within a wavelength interval, said wavelength interval coinciding with a transmission band of air, and said wavelength interval further coinciding with an absorption band of vapours containing molecules of a complex structure;
emitting UV light from said source such that UV light from the source can strike the UV sensitive photocathode; and
detecting, at said readout arrangement, a decrease of said signal between the detector and the source, whereby a presence of a vapour can be established. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
-
-
34. A photocathode excited by incident UV light, the photocathode comprising a conductive substrate coated with a layer of CsTe emitting photoelectrons characterised in that
said photocathode further comprises a coating of CsI on top of said CsTe layer.
Specification