Optical device for measuring slight pressure differences by means of light intensity changes
US4322978A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 27, 1980 |
| Grant date | Apr 6, 1982 |
| Priority date | — |
| Expiry date | Aug 27, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical device for measuring both slight positive and negative pressure differences by means of a light intensity change characterized by a gradient lens having a first and second end face being mounted in a housing part with a second end face spaced from a partially reflective membrane which is secured to the housing part to form a first chamber of a first volume and a second chamber of a second volume. An input waveguide such as an optical fiber is connected to a light source and is connected to the first end face of the lens and a pair of output waveguides are coupled to the first end face at two points displaced from the input fiber and a separate light intensity evaluation device connected to each of the output waveguides so that both positive and negative changes in pressure between the two chambers causes the membrane to be flexed and cause a reflective surface to move from a parallel position to cause a reflected image point of the input waveguide to move along the first end face with positive changes of pressure cause an increase of the intensity of the light being received by the one output waveguide and a negative pressure change causing the increased intensity in the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.