Investigation of the Stability of Thermistor Based Sensors for High-Precision Marine Temperature Measurement

Abstract

The ocean covers approximately 71% of the Earth's surface, acting as the largest heat reservoir with abundant natural resources and a complex ecosystem. As a fundamental hydrological parameter, ocean temperature fluctuations not only affect the measurement of other hydrological parameters but also profoundly impact the Earth's climate, ecosystems, and land-ocean interactions. Therefore, long-term and precise monitoring of seawater temperature is essential. This study evaluates the long-term stability of NTC thermistor temperature sensors, which are widely used for marine temperature measurements. The sensor performance was systematically studied under conditions of annealing pre-treatment, thermal shock, and constant-temperature aging. Experimental results show that approximately 140 hours of high-temperature annealing treatment can accelerate newly manufactured sensors to a more stable operating state. Glass-encapsulated sensors exhibited minimal drift under thermal cycling, with no noticeable drift caused by thermal stress, while epoxy resin-encapsulated sensors showed only marginal shifts within the millikelvin range. After pre-aging, the drift rate of the sensor exhibits a piecewise linear trend, with a rapid initial change followed by a gradual deceleration, ultimately stabilizing. Notably, the activation energy of the sensors in a high-temperature marine environment is approximately 0.3 eV. The temperature acceleration effect on the aging rate is significant at higher temperatures but negligible at lower temperatures. Our research provides both theoretical foundations and practical guidance for selecting high-precision temperature sensors, offering insights into sensor stability and optimization. This work contributes to the long-term accurate measurement of other marine parameters, providing reliable foundational support for oceanic physics, chemistry, and global climate research.

Keywords: Ocean Temperature, Thermistor Temperature Sensors, Stability, Accelerated Aging