Level sensor apparatus for detecting contact of a pipetting needle with a liquid in a vessel
US7416706B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 2005 |
| Grant date | Aug 26, 2008 |
| Priority date | — |
| Expiry date | Dec 23, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2035/1025
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A level sensor apparatus is disclosed for detecting contact of a pipetting needle with a liquid contained in a vessel. The apparatus includes a sensor head made up of a pipetting needle, a needle holder, and an electromechanical transducer. The sensor head also has an associated mechanical resonance frequency. An electrical signal generator is used to generate a driving signal which when applied to the electromechanical transducer causes vibration of the pipetting needle at the resonance frequency. A measurement device is used to measure a parameter of a vibration signal indicative of the mechanical vibration of the pipetting needle when it is driven by the driving signal. An electronic circuit and associated computer software is provided to evaluate variation of the vibration signal with time and thus detect contact of the pipetting needle with a liquid contained in the vessel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.