Radiation meters
US4935631A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 1988 |
| Grant date | Jun 19, 1990 |
| Priority date | — |
| Expiry date | Sep 26, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J1/58
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A radiation meter for measuring the intensity of incident ultraviolet radiation in a predetermined wavelength band against a background of broadband radiation, such as sunlight, includes a sheet of a material incorporating a fluorescent dye. The dye is selected to absorb radiation in the predetermined wavelength band and consequently to emit fluorescent radiation. The fluorescent radiation is internally reflected within the sheet and emerges from an edge of the sheet, where it impinges on a photodiode. The photodiode produces an output which is dependent upon the intensity of the ultraviolet radiation. This output is used to drive a suitable display. The unwanted background radiation passes through the sheet without causing fluorescence of the dye, and is absorbed in an absorbent backing layer. The photodiode is so positioned and screened that the background radiation cannot impinge upon it. A particularly advantageous use of the meter is for measurement of the intensity of ultraviolet band radiation, which is the cause of sunburn and skin cancer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.