Electrical resistance hardness tester for metallic materials
US5571954A · kind A · utility
Inventor
Key dates
| Filing date | May 9, 1995 |
| Grant date | Nov 5, 1996 |
| Priority date | — |
| Expiry date | May 9, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2203/0629
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A conducting tip of a hardness tester for metals, alloys and similar conducting materials is set forth. The tester comprises a resistance measuring circuit for measuring the resistance between the indenting tip and the test specimen when a certain load is applied to the indenter, made of a substantially insulating material with a superficial conducting film, the conductivity of which decreases toward the tip vertex. This contains the error induced by differences in temperature affecting the resistivity of the conducting superficial film. A tip of conical form with an angle which does not exceed 110 degrees increases precision, as compared with indenters constructed to the Vickers pyramid standard or to the Rockwell 120 degree cone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.