Surface condition measurement apparatus
US5314249A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1992 |
| Grant date | May 24, 1994 |
| Priority date | — |
| Expiry date | Nov 13, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2005/0074
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Radiated light with a specified wavelength from a material is detected and a first parameter corresponding to the emissivity ratio is obtained from the plurality of detection signals. Since the emissivity takes on different values according to the condition of the surface of the material, the first parameter changes depending on the surface condition of the material. There is a correlation between a physical value indicating a condition of the material surface and the first parameter. The correlation remains equivalent even if a second parameter corresponding to the physical value is used instead of the physical value itself (for example, an optical physical value such as reflectivity and absorptivity, the thickness of a film formed on the material surface, the surface roughness, and the degree of galvannealing). As an example of the parameter corresponding to the physical value, there is the logarithmic ratio between emissivities (ln .epsilon..sub.a /ln .epsilon..sub.b) corresponding to the temperature in the vicinity of the surface. Therefore, a second parameter can be obtained on the basis of the correlation and a physical value can be obtained. When the emissivity or logarithmi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.