Design of a Smart and High Precision Industrial Temperature Measurement and Monitoring System Using K-type Thermocouple and SPI-compatible Temperature Sensor

Abstract

This paper describes the design of a smart and high accuracy industrial temperature measurement and monitoring system using K-type thermocouple (TC). Normally errors are introduced due to non linear response of the thermocouple. We have linearised the amplified thermoemf using least square polynomial fitting algorithm. The reference junction temperature compensation is done by temperature to digital converter TMP121. Four temperature ranges are selected such that it can be implemented to a 12-bit ADC which operates from a 5 Volt DC source. The description of the system and accuracy obtained in four different temperature ranges is discussed.

Keywords

• Sensor linearisation
• Smart sensor
• Data acquisition circuits