Sensor apparatus
US7299678B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 27, 2001 |
| Grant date | Nov 27, 2007 |
| Priority date | — |
| Expiry date | Mar 27, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S73/01
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A measurement head particularly for borehole use can measure multiple parameters with no electronics in the head and only a single conductor cable. Double-ended tuning forks (26, 28 and 38, 40) in the head are arranged to respond to different parameters such as temperature and pressure by adjusting their resonant frequencies. A drive signal on the conductor (50) is applied to transducers (30, 32, 42, 44) on all the tuning forks and those whose instantaneous resonant frequency is close will resonate. The signal is removed and the transducers return a decaying signal at the resonant frequency along the conductor. Other drive frequencies are tried, to locate the other sensors whose frequency ranges are separate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.