A novel high-accuracy platinum resistance flexible temperature chain for polar temperature field measurement

Abstract

In order to effectively improve the accuracy of temperature measurement in the low temperature environment of the polar ice sheet, we designed a multi-point platinum resistance flexible temperature chain based on Pt1000, which has the advantages of low temperature resistance, low power consumption and high accuracy. The temperature chain consists of a master and multiple slaves. The master is used to read the entire temperature chain's data and make data exchange with the external equipment. The slave is used to collect and upload temperature data. RS485 bus communication is used between the master and slaves. The slave circuit directly measures the ratio of the bridge output voltage to the bridge input voltage to calculate the final temperature value, so the measurement accuracy is not affected by the fluctuation of the external power supply voltage. After the temperature measurement unit of each slave is calibrated using the least square method, when the temperature is greater than 0̂C, the temperature measurement error does not exceed 0.00134̂C, and when the temperature is less than 0̂C, the error does not exceed 0.07235̂C. In addition, low temperature experiments indoor as well as field tests have shown that the overall reliability of the temperature chain is higher for simultaneous temperature measurement at multiple points in the low temperature environment, which is suitable for detecting the temperature field profile of glacial ice and snow in the polar environment.