用于液体违禁品检测的电容传感器设计

Design of capacitance sensor for detecting liquid contrabands

提出了利用液体介电常数的电子测量,实现一种快速、无辐射、非接触、低成本的液体违禁品探测的新方法。在研究了液体介电常数测量的理论,并结合具体应用场合的基础上,提出了基于平面板电容器原理的平面板电容传感器和改进型的梳妆电容传感器电极,从理论的角度上对电极的参数进行了探讨。通过实验证明了改进型的梳状电极能够在不开瓶取样的情况下,有效鉴别出在厚度为4mm以下的非金属容器中浓度50%以上的酒精和水,可以用于非接触式液体违禁品快速检测。

A new method to detect the flammable and explosive liquid state goods is proposed through their dielectric constants.It has the advantages of high speed,non-radiation,non-contact and low cost.Based on the theory of liquid dielectric constant detection,the flat capacitance sensor based on the principle of flat capacitor and the improved multi-finger capacitor electrode are put forward.The key parameters of electrode are discussed theoretically.The experiments show that the improved multi-finger sensor can differentiate 50% alcohol which is filled in a sealed container with the wall thickness of 4 mm.It can be applied to a rapid detection of the contraband liquid goods.