两探头电涡流法食品罐头真空度无损检测

Eddy Current Method for Non-destructive Vacuum Determination of the Food Can with Two Sensors

利用电涡流法原理 ,开发出一种测量密封罐头内部压力或真空度装置。用第 1个传感器测量罐头柔性盖与该传感器之间的平均距离 ,第 2个传感器测量盖中心位置与该传感器之间的距离。 2个传感器输出电信号之差与内部压力或真空度成比例关系 ,进而得出罐头内部的压力或真空度。

An apparatus and method for determining the internal vacuum or pressure in a food can by using eddy current has been developed which measures the amount of deflection of the internal vacuum or pressure.The apparatus equips with two eddy current sensors. A first electrical signal represents the average of the distance between the flexible wall and a first sensor and a second electrical signal represents the distance between the center point on the flexible wall and a second sensor.The two signals are compared and a third signal indicative of the deflection of the flexible wall is provided. The principle and the sensor construction are given in the paper, respectively.