A high accurate temperature measuring system based on platinum resistance transducers is introduced,and used in the space-borne microwave radiometer.The measuring accuracy is ±0.1℃.The system adopts four-wire temperature measuring method using constant-current source to eliminate the measuring error caused by Pt resistance wire.The analog amplifying circuit and its measurement errors have been analyzed.The system has features of high precision,high reliability and good applicability,and it could be applied ...