Method and apparatus for determining viscosity
US4899575A · kind A · utility
40Cited by
11References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1988 |
| Grant date | Feb 13, 1990 |
| Priority date | — |
| Expiry date | Jul 29, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N11/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A capillary viscometer is provided which includes a fiber-optic probe and a phototransistor which produces an output signal as a liquid meniscus falls through the field of view of a detecting fiber bundle. An analog circuit is employed for receiving the signal and starting or stopping a digital counter in response thereto. The circuit includes first and second differentiators and a zero detection portion for detecting zero value outputs from the second differentiator. The counter is started or stopped upon the generation of a triggering pulse at the time such zero value is detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.