Performance evaluation of Raman scattering-based distributed optical fiber temperature sensing system in cryogenic environment

Abstract

Raman scattering distributed fiber optic temperature sensing technology has been widely used in many fields such as oil and gas transportation, public buildings, and fire monitoring of electrical equipment. However, the measurement performance of this technology is influenced by various factors at extremely low temperatures. In this study, a low-temperature experimental platform was independently built, and a 30-meter fiber optic was wound on a cryogenic cold head. The Raman scattering distributed fiber optic temperature sensing equipment was used to compare with the Cernox temperature sensor, and the low-temperature sensing performance of the fiber optic in the range of 5K to room temperature was examined. The experimental results showed that within a certain temperature range (room temperature to 65K), the system could provide accurate distributed temperature measurement. However, at low temperatures (65K to 5K), the increase in fiber optic stress and the decrease in Raman scattering intensity led to a reduction in signal-to-noise ratio, resulting in a sharp increase in measurement error and a significant impact on the measurement validity of the system. This study provides useful references and insights to further improve the measurement accuracy and stability of the Raman scattering distributed temperature sensing system at extremely low temperatures.