Signal circuit and cold junction compensation of fiber-optic thermocouple sensor

A fiber-optic thermocouple sensor is proposed in this paper, which is composed of a number of optical fiber and thermocouple sensor. A signal processing circuit of the fiber-optic thermocouple sensor is designed and a cold junction compensation method is also introduced. This paper focuses on analyzing optical fiber sensor signals and the cold junction compensation method in the case of multi-channel temperature measurements. The cold junction compensation method is based on the Newton iterative algorithm, which is embedded in a microprocessor. An experiment of temperature measurement is fulfilled and hence testifies the feasibility of the proposed fiber-optic thermocouple sensor and its cold junction compensation method.