An accurate diode thermometer for use in thermal gradient chambers

A thermometer has been constructed that is suitable for use in thermal gradient chambers. The water-proof sensing element is a forward-biased constant-current Schottky-junction hot-carrier diode. The voltage across the diode decreases with temperature in an approximately linear fashion and, with suitable corrections for the diode used, enables probe temperatures to be determined to within +or-0.05 degrees C over the range -65 to +50 degrees C.