Non-contacting resistivity instrument with structurally related conductance and distance measuring transducers
US4302721A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1979 |
| Grant date | Nov 24, 1981 |
| Priority date | — |
| Expiry date | May 15, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S414/135
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An instrument for computing resistivity based upon measurements of thickness and conductance. A conductance transducer is a solenoid in an annular ferrite cup connected to a tank circuit for an eddy current measurement of conductance. Within the center of the annular ferrite cup concentric acoustic wave sending and receiving channels are disposed for making an acoustic pressure wave measurement which is used for a thickness measurement using two gauge heads, spaced on opposite sides of an article to be measured. Each gauge head contains identical conductance and thickness transducers. The thickness measurement is divided by the conductance measurement to derive resistivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.