Detector
First Claim
Patent Images
1. A detector comprising:
- a housing;
a flame detector sensor mounted within the housing and configured to detect an external flame;
a first temperature sensor configured to sense temperature of the flame detector sensor;
a second temperature senor configured to sense ambient temperature;
a heater positioned adjacent to the flame detector sensor; and
a controller in communication with the first temperature sensor and the second temperature sensor, and configured to vary power supplied to the heater;
wherein the controller is further configured to;
compare the ambient temperature as indicated by the second temperature sensor to the temperature of the flame detector sensor as indicated by the first temperature sensor, wherein the ambient temperature is varying;
in response to the comparison, determine an amount of power to the heater in order to control a rate of change of the temperature of the flame detector sensor to be within a predetermined limit;
control the power supplied to the heater at the determined amount of power to change the temperature of the flame detector sensor at the rate of change to a different temperature so that the different temperature of the flame detector sensor is within a predetermined temperature difference relative to the varying in the ambient temperature.
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Abstract
A detector comprises a housing (1), a pyroelectric array sensor (2) mounted within the housing, a heater (4) associated with the pyroelectric array sensor, and control means (6) for varying the power supplied to the heater to control the temperature of the pyroelectric array sensor relative to the ambient temperature in order to minimise the rate of change of temperature of the pyroelectric array sensor and to keep a predetermined difference between the temperature of the pyroelectric array sensor and the ambient temperature.
62 Citations
23 Claims
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1. A detector comprising:
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a housing; a flame detector sensor mounted within the housing and configured to detect an external flame; a first temperature sensor configured to sense temperature of the flame detector sensor; a second temperature senor configured to sense ambient temperature; a heater positioned adjacent to the flame detector sensor; and a controller in communication with the first temperature sensor and the second temperature sensor, and configured to vary power supplied to the heater; wherein the controller is further configured to; compare the ambient temperature as indicated by the second temperature sensor to the temperature of the flame detector sensor as indicated by the first temperature sensor, wherein the ambient temperature is varying; in response to the comparison, determine an amount of power to the heater in order to control a rate of change of the temperature of the flame detector sensor to be within a predetermined limit; control the power supplied to the heater at the determined amount of power to change the temperature of the flame detector sensor at the rate of change to a different temperature so that the different temperature of the flame detector sensor is within a predetermined temperature difference relative to the varying in the ambient temperature. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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2. A detector as claimed in claimed 1, wherein the predetermined temperature difference is dependent upon the largest temperature change that the detector has been designed to sustain in its intended operating environment.
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15. A detector as claimed in claimed 1, wherein the controller is configured to track the ambient temperature and to determine how the ambient temperature is changing.
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16. A detector as claimed in claimed 1, wherein the controller is configured to dynamically select the predetermined temperature difference.
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17. A detector as claimed in claimed 16, wherein the controller is configured to dynamically select the predetermined temperature difference based on the ambient temperature.
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18. A detector as claimed in claimed 17, wherein the controller is configured to reduce the predetermined temperature difference to zero when the ambient temperature is a predetermined temperature.
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19. A detector as claimed in claimed 17, wherein the predetermined temperature difference is a non-zero difference.
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20. A detector as claimed in claimed 1, wherein the controller is configured to determine the rate of change based on a sensitivity of the flame detector sensor.
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21. A detector as claimed in claimed 1, wherein the second temperature sensor is positioned within the housing.
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22. A detector as claimed in claimed 1, wherein the housing comprises a window;
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wherein the flame detector sensor is mounted within the housing relative to the window through which the flame detector sensor is configured to detect an external event. - View Dependent Claims (23)
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Specification