Self-compensating optical drop count apparatus for measuring volumetric fluid flow
US4314484A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 9, 1979 |
| Grant date | Feb 9, 1982 |
| Priority date | — |
| Expiry date | Oct 9, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S128/13
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A self-compensating optical drop count apparatus for measuring volumetric fluid flow by optically counting the number of drops of fluid that pass through a drop chamber, each drop being formed so as to be of approximate equal volume. Optical counting circuitry is designed to count each drop only once. The count is accumulated in a holding register where it may interface with external instrumentation equipment adapted to display the count and/or convert it to a volumetric measurement by multiplying it by the average volume of fluid contained in each drop. A compensation technique is utilized to maintain the intensity of a light beam, through which the drops must pass, at a constant level. Compensation is achieved in a closed loop system which varies the drive current to the light emitter to compensate for long-term variations that occur in the intensity of the light beam as sensed at a light detector. Compensation techniques are also utilized in converting the count to a volumetric measurement to account for known changes in drop volume as a function of drop rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.