Design and application of high-precision temperature measuring instrument for ice cover profile of river based on the resistance residual compensation method

Abstract

Based on the temperature characteristics of the air, ice and water in the vertical direction of the river ice cover, an automatic temperature measuring instrument for ice cover profile was designed. The sensor used NTC thermistor as a temperature detection unit. In order to improve the actual detection accuracy of the sensor units in a wide temperature range [223.15 K (-50°C), 293.15 K (20°C)], a calibrating method of the thermistor using the resistance residual compensation method was proposed and compared with the existing seven calibration methods. The results show that the accuracy of the calibrated temperature sensor units can reach 0.1 K in the testing range, which can satisfy the accuracy requirements in thermodynamics research of ice cover profile. We further designed a temperature measuring instrument and carried out a deployment of the instrument and in-situ observation of data in cold region of the upstream of Heilongjiang River in late December 2017. The evolution process of ice thickness was analysed and discussed by the collected data. It can be proved that this instrument is an effective scheme for intelligent detection of river ice environment in cold regions.