| 摘要 |
PURPOSE:To furnish a method for controlling concentration for a chemical solution tank of a chemical solution being used in circulation and equipment therefor. CONSTITUTION:A method for controlling concentration wherein the concentration of a solution is detected by measuring the absorbance or transmittance thereof and controlled, and a method for changing measuring sensitivity by adjusting a distance between a light applying part and a light-sensing part or by changing a measuring wavelength. Equipment for measuring the concentration of a chemical solution which has a light source 1, the light applying part 2 having an optical fiber connected to the light source 1 and a pickup lens provided in the end, a light-sensing part 3 made up of a light-sensing pickup lens and an optical fiber, a photosensor 6 measuring the intensity of light from the light source 1 and the intensity of the light detected by the light-sensing part 3, and a computer for obtaining absorbance or transmittance from the intensity of the light. Concentration measurement wherein the measuring sensitivity is changed by adjusting the distance between the light applying part 2 and the light-sensing part 3 or by changing the measuring wavelength is obtained. |
