Inexpensive digital thermometer for measurements on semiconductors
I. C. D. HADLEY, Robert D. Gould · International Journal of Electronics · 1991
An inexpensive digital thermometer for measurements on semiconductors has been designed and constructed using standard integrated circuits and a liquid crystal display panel. The equipment, which operates over the temperature range − 200°C to + 200°C, utilizes a type-K thermocouple as the temperature sensor and features electronic cold junction compensation. An analogue signal derived from the thermocouple is routed to an analogue-to-digital converter (ADC) whose output codes correspond to EPROM addresses in which linearized temperature output codes are stored. The instrument is accurate to ±1°C over the entire temperature range when a 10-bit ADC is used, although in principle this may be improved to ±0.1°C by the use of a 14-bit ADC.