Dynamic measurement of density using terahertz radiation with real-time thickness measurement for process control
US9417181B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 2014 |
| Grant date | Aug 16, 2016 |
| Priority date | — |
| Expiry date | May 8, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/06113
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of determining a density of a roller compacted ribbon is disclosed. The method comprises compacting dry pharmaceutical powder between press rollers of a roller compactor to produce a compact ribbon. The method also comprises determining a thickness at a point on the compact ribbon in a non-invasive manner after it has rolled out from in between the press rollers. Further, the method comprises passing the compact ribbon through a gap in between the terahertz emitter and the terahertz detector. Next, the method comprises determining a refractive index at the point on the compact ribbon using a measurement value from the terahertz emitter and the terahertz detector and a measured value for the thickness at the point. Finally, the method comprises computing a density of the compact ribbon at the point using a value of the refractive index.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.