Method for thickness calibration and measuring thickness of material
US8077827B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 23, 2010 |
| Grant date | Dec 13, 2011 |
| Priority date | — |
| Expiry date | Aug 2, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B15/025
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for measuring the thickness of a first absorbing material in the presence of a second absorbing material is provided. The method comprises the steps as follow. The thickness (tS) of the first absorbing material is fixed and the thickness of the second absorbing material is varied to obtain a calibration standard. The intensity of the transmissive energy passing through the calibration standard is detected by acquiring multiple pairs of image data comprising a foreground value (logn(Ic+s)) and a background value (logn(Ic)). The thickness (tSi) of the first absorbing material is changed and the above steps are repeated to obtain sets of image data. A fitting constant Id is determined to describe each set of the intensity data asA best fit of the proportional constantis determined to further calculate an unknown thickness of the first absorbing material (ts′) through the equation
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.