An Accurate Fast Response Temperature System Using Thermocouples

Abstract

Abstract An accurate and fuss response thermocouple-based temperature system has been developed for use in the atmospheric surface layer. The absolute accuracy is better than ±0.01°C and the relative accuracy between thermocouples is ±0.01°C. A number of special features were incorporated into the system to achieve the required performance. These include front-end multiplexing to allow one amplifier to process all channels; microprocessor-based control; handling of large, fast-changing temperature variations with no degradation in performance; and sophisticated noise removal and error reduction techniques. The system can accommodate up to 22 thermocouples with a total data rate of 180 s−1. Humidity is measured by converting standard thermocouples to wet bulbs through the use of wetted wicks.