1,208,846. Measuring temperature electrically. INTERNATIONAL BUSINESS MACHINES CORP. April 30, 1969 [Aug. 26, 1968], No.21911/69. Heading G1N. [Also in Division H3] In a threshold detector (see Division H3) the current in a differential amplifier 14 is controlled by a temperature sensitive constant current unit 18 so as to compensate for temperature variations in the detector. It is explained that the emitter have voltage of 37 varies with temperature and that by selecting the value of resistor 42 the desired relation between the collector current of transistor 38 and temperature may be obtained.