The Research Of Test Methods For Thermistor Infrared Detectors And Equipment Development

The detector with double thermal resistors is one of the most important device ofthe Train Hotbox Detecting System. Its reliability and stability is directly related tothe normal running of the system and the safety of the train operation. By now, thescreening and testing methods of this detector is old and has some defections. And itis not perfect for the use in Train Hotbox Detecting System. It is hard to fit the need ofthe high standard, high reliability and high safety using by China Railway.The equipment of the IR detector testing is researched and developed by smallsignal technology and shielding technology. The purpose of making this equipment isto serve a more advanced and reliable support to the testing of the thermal IR detector.And after the research of the testing method, we can get a detail way to theequipment-making. What is more, it is a new and suited method for the engineeringuse. It has proved an important significance to the using in Hot-Box detecting andimproving the period of the detector.This study gives a test method fitted to the engineering application of TrainHotbox Detecting System and designs an equipment fitted to the test method. Themain content of the paper is as follows:(1)Introduces the application of the thermistor infrared detector in China Railwayand its background and significance of the test method. Introduces the thermistorinfrared detector’s structure, sort, working principle, fail theory and application inTHDS–A. Analyses the significance for the test method’s improvement.(2) The noise of the thermal resistor is briefly introduced, then some theories oftest for the noise are explained. Combining with the actual，we get a conclusion ofusing1/f noise as our main test target and confirm its threshold.(3) Theinfluence of heat to the detector is introduced. From the noise and heatmodel, we get some values of the bias voltage either for testing and engineering. Thenusing the result of some accelerated aging tests, a model of burn-in for the detector which is important to the testing method is given and a method of burn-in forthermistor detector is put forwards.(4) Based on the conclusion of the pre-chapters, a design scheme of testequipment is made and gives a detail of development and test for the use of testing thedetectors. Then a final and completed test method for RHT-Z detector is given.