A linear temperature transmitter based on Pt100
Liu Ximin, Ren Hongwei, Zhang Enping · 2008
A temperature transmitter is introduced for linear temperature measurement with high accuracy by using platinum thermal resistor. It consists of AD580, resistor, amplifier, AD converter, data sampling and processing system, digital display, serial output port, DA converter, 4–20mA.DC output and so on. The method of single comparing is used to find thermal resistance value with high accuracy; then the value is mapped to the corresponding temperature by looking into reference table. Therefore, linearity is implemented, which greatly reduces the impact of temperature-drift and non-linearity in amplifier. In addition, the device implements the measuring of full temperature range of the reference table. The test error is ±6°C in −200°C ∼850°C with B class platinum thermal resistor.