| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for automatically diluting a cleaning solution of high concentration with pure water without drawing air bubbles into a mixed solution in order to prepare a dilute mixed solution of the cleaning solution of extremely low concentration (1,000 ppm or less) that is difficult to control with various analyzers. SOLUTION: The cleaning solution of high concentration and the pure water are added to the mixed solution without forming air bubbles not by directly injecting both liquids into a mixing tank 2 but by injecting each liquid through a check valve to a circulation line 17 and extending a discharge pipe of the above circulation line 17 in the mixing tank to below the liquid level of the mixing tank 2. A load cell and a level gage are used as a main instrument and a subinstrument respectively for measuring the pure water, whereas a metering pump and a load cell are used as a main instrument and a subinstrument respectively for measuring the cleaning solution of high concentration. COPYRIGHT: (C)2007,JPO&INPIT |
