Apparatus for measuring surface reflectance characteristics
US4455090A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 17, 1980 |
| Grant date | Jun 19, 1984 |
| Priority date | — |
| Expiry date | Jul 17, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/55
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An instrument for measuring surface characteristics based on the opacity of a material has an optical projection system for illuminating a sample and photocell arrangement for measuring light reflected from the sample. The instrument contains standard black and white surfaces with reference to which the sample opacity is measured. The photocell signal is digitized and the results processed and calculations made by a microprocessor system enabling sets of results to be stored and mean and standard deviations to be calculated. The instrument is particularly intended for testing paper and, in connection with carbonless copy paper, enables a measure to be made of the density of an imprint relative to the background that is called calender intensity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.