Stability Evaluation And Experimental Study Of The Eddy Current Sensor

The eddy current sensor is created based on the eddy current effect. It has a wide range of uses, such as measuring various kinds'physical quantities: position, vibration, rotational speed, temperature, bilge sent, testing and thickness of various. It is simple in structure and has several advantages, such as good reliability, high sensitivity, not polluted, strong anti-jamming capability etc. But because of the limitation of various factors in the developing process, the eddy current sensor has some undeniable problems:Its various performance indicators, especially for the working environment temperature bear on measurement precision of the eddy current sensor, this influence should be particularly notable.Due to the environmental conditions of eddy current sensor is bad, for example in the environment is larger changes in the environmental temperature, its stable performance application face to the acid test. To reduce and inhibit the eddy current sensor temperature drift at home and abroad have had much research, there are more common methods, like work for probe coil, including several strands of line, differential detector; to add compensating lead device in the link.According to the problems, and analysis and comparison of all present technical means, this paper designed the stability experiment of the eddy current sensor, and though the experiment to evaluate the stable performance, including sensitivity, linearity, repeatability and hysterisis error. In order to determine the temperature performance of this eddy current sensor, this paper set up two groups of the same experiment for the sensor of two different series, and then to explore influence the stability of the main factors from these experiments.The theoretical and experimental proof, the main factors affecting the stable performance is probe. Through to analyze probe coil equivalent circuit and impedance characteristics, this paper puts forward the coil material properties produce very big effect to temperature performance, in this paper the alloy materials selected to improve temperature performance has obvious effect.The experimental results show that the temperature stability performance is far superior to the original coil when using these measures.