US 7,119,326 B2Granted

Method and apparatus for testing an infrared sensor

AssigneeDelphi Technologies, Inc.

InventorsJames H. Logsdon, Pedro E. Castillo-Borelly, Abhijeet V. Chavan, Michael P. Donahue, Deron K. Slaughter

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Abstract

A method and apparatus for evaluating the functionality and sensitivity of an infrared sensor to infrared radiation. The method and apparatus are adapted for testing an infrared sensor having a diaphragm containing a heating element and a transducer that generates an output responsive to temperature. The method entails placing the infrared sensor in a controlled environment, and then exposing the diaphragm of the sensor to different levels of thermal radiation so as to obtain outputs of the transducer at different output levels. In the absence of exposure of the diaphragm to thermal radiation, flowing current through the heating element at different input levels so that the output of the transducer returns to the different output levels obtained using thermal radiation, the input difference between the input levels can be computed and used to assess the functionality and the sensitivity of the sensor.

Claims27

Dependent claims

A method of testing a first infrared sensor having a diaphragm containing a heating element and a transducer that generates an output responsive to temperature, the method comprising the steps of:

placing the first infrared sensor in an environment so as to cause the diaphragm to be at an environment temperature and so that the output of the transducer is at an environment-induced output level;
exposing the diaphragm of the first infrared sensor to thermal radiation emitted by a first body so as to cause the diaphragm to be at a first temperature that is different from the environment temperature and the output of the transducer is at a first output level that is different from the environment-induced output level;
exposing the diaphragm of the first infrared sensor to thermal radiation emitted by a second body so as to cause the diaphragm to be at a second temperature that is different from the environment temperature and different from the first temperature and the output of the transducer is at a second output level that is different from the environment-induced output level and different from the first output level;
and
while the diaphragm is not exposed to thermal radiation from the first and second bodies and the diaphragm is substantially at the environment temperature, causing current to flow through the heating element at a first input level so that the output of the transducer is substantially at the first output level, and causing current to flow through the heating element at a second input level so that the output of the transducer is substantially at the second output level.

2 more elements

An apparatus for testing an infrared sensor having a diaphragm containing a heating element and a transducer that generates an output responsive to temperature, the apparatus comprising:

an environment at an environment temperature so that placing the infrared sensor in the environment causes the diaphragm to be at the environment temperature and so that the output of the transducer is at an environment-induced output level;
means for exposing the diaphragm of the infrared sensor to thermal radiation emitted by a first body at a temperature that is different from the environment temperature so as to cause the output of the transducer to be at a first output level that is different from the environment-induced output level;
means for exposing the diaphragm of the infrared sensor to thermal radiation emitted by a second body at a temperature that is different from the environment temperature and different from the temperature of the first body so as to cause the output of the transducer to be at a second output level that is different from the environment-induced output level and different from the first output level;
means for substantially preventing exposure of the diaphragm to thermal radiation emitted by the first and second bodies so as to cause the diaphragm to be at the environment temperature;
means for causing current to flow through the heating element at a first input level so that the output of the transducer is substantially at the first output level;
and
means for causing current to flow through the heating element at a second input level so that the output of the transducer is substantially at the second output level.

4 more elements

Dependencies are inferred from the claim text.