| 摘要 |
PROBLEM TO BE SOLVED: To provide a liquid level detection sensor which is not eroded with the lapse of time by a chemical used in a semiconductor washing process or the like, thereby not contaminating the chemical, which does not malfunction, and which can accurately and stably detect the liquid level, and to provide a method for detecting the liquid level. SOLUTION: The sensor for detecting the liquid level is composed of a glass tube 2 whose tip part is at least closed, a bar-like optical liquid level sensor body 3 accommodated in the glass tube, and a medium liquid 4 introduced between the glass tube and the sensor body. The sensor detects the liquid level of the chemical according to whether or not a light emitted from the body is transmitted through the tube wall 6 at the tip part of the glass tube. As the glass tube 2, a transparent quartz glass tube is used. As the medium liquid 4, pure water is suitable. COPYRIGHT: (C)2004,JPO |
