| 摘要 |
PURPOSE:To wash a material to be washed positively by a minimum quantity of pure water by completing washing when the resistivity value of pure water before washing the material to be washed and pure water after washing reaches a set value. CONSTITUTION:A carrier 3 holding masks 2 is housed into a washing tank 1, and pure water is fed into the tank 1 from a supply pipe 4, and discharged to a discharge pipe 5. Since a difference is formed between the resistivity values of resistance meters 6 and 7 at a point of time when the washing of the masks 2 is started, a solenoid valve 9 is opened, and pure water continues to be fed. Since an electrolyte is removed from the masks 2 in a short time, the resistivity values of the resistance meters 6, 7 gradually reduce or do not change. The time displays the completion or limit of washing, and the solenoid valve 9 is closed and washing is completed when the resistivity values reach a set value set to a controller 8. Accordingly, a material to be washed is washed positively while the consumption of pure water more than required can be prevented. |
