The Sensing Characteristics of Ring-Core Fluxgate Sensors at Temperature Interval of −50 °C to +85 °C

Fluxgate magnetometers are widely used in many places for the measurement of weak magnetic field, but are sensitive to variations in sensor temperature. Therefore, their stabilization against temperature is required especially for outdoor applications. In this paper, temperature dependencies of fluxgate sensors using four cobalt-based cores, two homemade, and two commercially obtained were analyzed at temperature interval of −50 °C to +85 °C in the climatic chamber. In addition to differences seen on the temperature dependence of the studied cores, the most stable one was the sensor using Co 65 Fe 6 Cr 7 Si 8 B 14 core. Although the variation of the scale factor in the 135 °C temperature range was 17% in magnitude, it was decreased to 6% with a serial resistor connected to the pick-up coil, where the sensor signal is induced by measured dc field. By specifying the scale factor versus temperature dependence curves, we could decrease the error coming from temperature variations to less than 2%. Experimental results reveal that the sensors cored with Vitrovac6025 and Metglas2714A ribbons can also be preferred when they are evaluated in terms of both temperature dependence and noise levels.