Methods and apparatus for calibrating an electromagnetic measurement device
US7274453B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Oct 14, 2004 |
| Grant date | Sep 25, 2007 |
| Priority date | — |
| Expiry date | Oct 27, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J3/447
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Methods and apparatus for measuring an electromagnetic radiation response property associated with a substrate and calibrating an electromagnetic measurement device are disclosed. The methods and apparatus generate electromagnetic waves and capture a portion of the generated waves after the waves pass through a first polarized filter, reflect from a substrate, and pass through a second polarized filter arranged in a cross polar arrangement with respect to the first polarized filter. In addition, the apparatus captures electromagnetic waves that pass through an attenuating filter and reflect from one or more calibration standards. Digital data is determined from the captured electromagnetic waves. The digital data is used to recalibrate the apparatus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.