METHOD AND DEVICE FOR EVALUATING METAL WASHING PROCESS

PURPOSE:To continuously measure the residual amount of deposits during washing of metal by counterposing two metal plates including a metal plate with a deposite having a different conductivity from that of a washing liquid and then feeding a sinusoidal wave AC at a specific frequency for measuring impedance. CONSTITUTION:A substance to be eliminated (for example oil) is filled inside a clearance 5 which is formed by adhering two metal plates 3 to both sides of a plate 4 of a nearly U-shaped insulation material and a measurement cell 7 where areas other than the clearance 5 and an entrance 5a are covered with an insulation material 6 is laid out inside a washing liquid 2 inside a washing device 1. Then, a high-frequency sinusoidal wave AC 12 is fed to the cell 7 and current flowing to an electrical circuit 11 and voltage between the metal plates 3 are obtained by a microcomputer 23, and then a resistance Rs (impedance of the cell 7) of the substance inside the clearance 5 is calculated by a high-speed Fourier Transformation, etc. Then, by referring to the relationship between the amount of substance inside the clearance 5 obtained in advance and the resistance Rs, the remaining amount of substance (oil) can be measured continuously during washing and the metal washing process can be evaluated continuously.