圆台状脉冲涡流差分传感器设计

Design of a cone-shaped pulsed eddy current differential sensor

当采用脉冲涡流差分传感器进行缺陷检测时,被测试件的属性会对检测信号特征产生一定的影响,为降低其影响,提高差分传感器的缺陷检测能力,本文设计了一种圆台状差分传感器。首先根据电磁波的反射与折射理论建立了圆台状差分传感器的磁场解析模型,而后通过分析传感器线圈倾斜角与差分检测信号特征之间的关系确定了传感器的最优结构,最后通过实验对圆台状差分传感器的性能进行了测试。实验结果表明:圆台状差分传感器可有效降低被测试件属性信息对检测信号的影响,且具有较强的缺陷检测能力和抗提离干扰能力。

When the pulsed eddy current differential sensor is used to test defects, the differential testing signal feature will be influenced by the attribute of specimen. In order to reduce the influence of the attribute of specimen and improve the capability of defects testing of the differential sensor, the cone-shaped differential sensor is proposed. The analytical model of cone-shaped differential sensor is established based on the reflection and transmission theory of electromagnetic waves. The relationship between inclined angle of the coils and character of the differential signal is analyzed, and the optimal structure of the sensor is obtained. The experiment is performed to verify the performance of the proposed sensor. Experimental result indicates that the effect of sample attribute on testing signal feature can be effectively reduced, and the performance of defects testing and lift-off interference suppression of the designed sensor is high.