INDIGENOUS DEVELOPMENT OF THE AIRCRAFT STANDARD 'DUAL TEMPERATURE SENSOR' (THERMISTOR) FOR THE RADAR COOLING SYSTEM (RCS) OF TYPICAL FIGHTER AIRCRAFT

摘要

The Dual Temperature sensor is mounted in the Pump-Motor unit of Radar Cooling System. The Sensor is used to sense the inlet temperature of the coolant for the Radar. It consists of two thermistors elements in a single housing. These thermistors have a negative temperature coefficient characteristic. The design requirement of thermistors is of 30Kohm ± 5% at 25℃. Working temperature range is -40 to 80℃, working line pressure is 10 bar g. Insulation resistance is greater than 20Mohms, Weight is less than 200gms. The design is according to the requirements of MIL-STD-810E, Environmental Standard. In this standard, temperature range is -55℃ (storage) to 80℃, the acceleration is of-3.5g to 9g, and the altitude level is 18Km above sea level. The acceptance tests such as the measurement of Insulation resistance, Calibration check, Cyclic test etc and Qualification tests such as the high temperature, low temperature, thermal shocks, humidity, acceleration, vibration, shock, fungus, salt fog, transit drop, endurance tests of 1000 cycles at 0℃ and 80℃, are successfully done according to the Military standards, which demonstrate the functionality within performance specification limits and under simulated environmental conditions. In every stage of development there is an involvement of Quality Assurance Department (QA), Chief Resident Inspector (CRT), Regional Center for Military Airworthiness (RCMA), and all the necessary approvals of Drawings, process sheets, test Documents etc. have been taken and all test reports have been prepared, which authenticates that the unit is functioning satisfactorily as per the Airworthiness requirement.