Magnetic debris monitor using magneto-optic sending
US5214377A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1991 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Jun 3, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/0322
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A debris monitor apparatus and method and optical sensor apparatus and method that use the Faraday Effect to detect accumulation of debris on a magnetic probe. The probe contains a magnet and the optical sensor and is immersible in the fluid. As debris accumulates on the probe, the magnetic field changes. The optical sensor includes a magneto-optic material located within a portion of the changeable magnetic field, preferably near a node of the magnet. Means are provided to bi-directionally address the sensor magneto-optic material with linearly polarized light. Means are also provided to convert rotation of the light polarization angle into a modulation of the light's intensity. An electro-optic transducer converts the light intensity into electrical signals that indicate the quantity of debris accumulation on the probe, with a differentiated value of these signals with respect to time yielding rate of debris accumulation on the probe. Means are provided to calculate a ratio defined by the difference over sum of two bi-directionally transmitted pulses to provide a self-referenced output dependent only on the change in magnetic field caused by accumulation of debris on the probe. T…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.