Optical attenuation coefficient meter
US9909927B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 2016 |
| Grant date | Mar 6, 2018 |
| Priority date | — |
| Expiry date | Aug 1, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/0642
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An attenuation meter is provided for use in a water environment. In operation, a transmitter of the meter transmits a laser pulse focused to a size at a predetermined range. A receiver of the meter images a focused spot to minimize unwanted light back scattering and avoid diffractive spreading within the back scattering region. Filtering the angular region can further reject scattered light. The filtered light is received, measured and processed by a oscilloscope as pulse averages. The meter also includes a photodetector to measure a diffuse attenuation coefficient. The output voltage of the photodetector is measured and processed by the oscilloscope that produces an average voltage over a preset number of pulses. A controller best fits voltage to time dependence to produce the diffuse attenuation coefficient. Only the shape of the receiver time dependence is required to provide the diffuse attenuation coefficient measurement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.