Long-line resistance temperature measurement method and system based on reflection coefficient spectrum

Abstract

This invention belongs to the field of long-distance temperature measurement technology and discloses a long-line resistance temperature measurement method and system based on the reflection coefficient spectrum. It utilizes a coaxial cable as a long-distance lead connected to the temperature-sensing resistor, and obtains the reflection coefficient at the beginning of the coaxial cable. A fast Fourier transform is performed on the real part of the obtained reflection coefficient at the beginning to determine the equivalent frequency. The length of the coaxial cable is determined based on the equivalent frequency. Based on the length of the coaxial cable, the real part of the attenuation-compensated reflection coefficient spectrum at the beginning is determined, and then the reflection coefficient at the end of the coaxial cable is determined. The resistance value of the temperature-sensing resistor is then determined based on the reflection coefficient at the end of the coaxial cable. Finally, the corresponding temperature is determined based on the resistance value of the temperature-sensing resistor. This invention uses a coaxial cable as a long-distance lead and combines the extremely narrow-band filtering characteristics of the reflection coefficient spectrum itself to effectively reduce electromagnetic interference, while introducing an attenuation compensation function to improve temperature measurement accuracy.

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