Photometer
US4043676A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 1975 |
| Grant date | Aug 23, 1977 |
| Priority date | — |
| Expiry date | Jul 18, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/274
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A photometer for measuring the light transparency of a substance. A light beam is provided for illuminating a substance, which light beam passes through the substance and strikes a photoelement and produces a measuring current. The voltage generated from the measuring current is logarithmated by a converter circuit and is supplied to an indicating instrument for indicating a measured value. A zero balance control circuit is provided for controlling the voltage applied to the indicating instrument so that the indicating instrument will return to a value determined by a previous measuring of a calibrated substance. If the transparency of the measured substance is identical to the transparency of the calibrated substance, the indicating device will return to a zero value. A value other than zero will indicate the difference in transparency of the measured substance from the calibrated substance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.