The pt100 temperature sensor is an instrument that converts a temperature variable into a transmittable, standardized output signal. Mainly used for the measurement and control of industrial process temperature parameters. Transmitters with sensors usually consist of two parts: the sensor and the signal converter. Sensors are mainly thermocouples or thermal resistances; signal converters are mainly composed of measuring units, signal processing and conversion units (because industrial thermal resistances and thermocouple scales are standardized, signal converters are also called as independent products. Transmitter), some transmitters add display unit, and some also have fieldbus function.

Constant current and constant voltage method

In traditional instruments and meters, this method is generally used. After the constant current or constant voltage method is constructed, the resistance value of Pt100 (PT100 temperature sensor) is calculated by using Ohm's law, and then the index table is queried to obtain the temperature. This method is simple and general.

Universal sensor interface UTI method

Although the traditional method is simple, it has many shortcomings. Using the universal sensor interface chip, only a reference resistor that is not sensitive to temperature is needed, and the Pt100 (PT100 temperature sensor) is connected to the UTI circuit, and the ratio of the Pt100 to the reference resistor can be obtained through the MCU, thereby obtaining the resistance value and temperature. This method is very suitable for microprocessor-based (MCU)-based systems. All the information of the UTI is output only through a MCU-compatible signal, which greatly reduces the external wiring and couplers between discrete modules.