Humidity Sensitivity and Coil Design of a High-Precision Eddy-Current Displacement Sensor

Proceedings

Vogel, Johan G.¹ 

关键词: displacement sensor;    eddy-current sensor;    parasitic capacitance;    self-resonance frequency;    humidity sensitivity;    planar coil;   

DOI  :  10.3390/proceedings1040283

学科分类：社会科学、人文和艺术（综合）

来源: mdpi

【 摘 要 】

Unlike capacitive displacement sensors, Eddy-Current Displacement Sensors (ECDSs) possess an inherently low sensitivity to environmental conditions, such as the humidity of the ambient air. By elevating the excitation frequency it is possible to mitigate their major limitations regarding stability and resolution, making them of interest for high-precision displacement sensing. However, by increasing the excitation frequency, ECDSs become less immune to environmental conditions, due to the inevitable parasitic capacitance of the sensing coil. In this work, we formulate a requirement for the minimum Self-Resonance Frequency (SRF) of the coil, based on the specified humidity variation and the allowable displacement error. This requirement provides an input for the design of the high-precision ECDS probe.

【 授权许可】

CC BY