Liquid level detecting device and a processing apparatus
US5234527A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jul 17, 1991 |
| Grant date | Aug 10, 1993 |
| Priority date | — |
| Expiry date | Jul 17, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/2001
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A liquid level detecting device used in a vacuum processing apparatus, the device comprising a liquid container section, an inlet pipe for liquid supply connected to the liquid container section, and outlet pipe for discharging the liquid when the liquid in the liquid container section overflows a predetermined liquid level, a temperature measurement terminal provided in the liquid container section, for detecting the temperature of the liquid in the container section, means for heating or cooling the temperature measurement terminal, and a liquid level detecting section for detecting the surface level of the liquid on the basis of the difference between two temperatures of the liquid measured when the heating or cooling means is in contact with the liquid and when not in contact.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.