Electronic hydrometer and method of determining the density of a liquid
US4400978A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 1, 1981 |
| Grant date | Aug 30, 1983 |
| Priority date | — |
| Expiry date | Sep 1, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N9/20
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electronic hydrometer for determining the density of a liquid, the hydrometer comprising a housing having a liquid receiving chamber and means to insert a liquid of which the density is to be determined in the chamber. A float having a known weight is disposed in the chamber. A connecting shaft is secured to the float and retained for guided displacement along its longitudinal axis in response to introduction of a predetermined quantity of liquid in the chamber. A sensor is associated with a shaft for detecting a reference position of the shaft. A permanent magnet is mounted in proximity of the shaft and has a magnetic core and a displaceable coil about the core. The coil is secured to the shaft. An electronic circuit means automatically adjusts the value of a current flowing in the coil to displace the coil and the shaft relative to the reference position. The value of the adjusted current is calibrated by the circuit to generate an output signal indicative of the density of the liquid in the chamber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.