Device for and method of measuring minute elongations by means of light wave conductor sensors

US4900920A · kind A · utility

Assignee

• Felten & Guilleaume Energietechnik GmbH · DE

Inventors

• Helmut Federmann · Bensberg, DE
• Friedrich K. Levacher · Bad Sobernheim, DE
• Georg Noack · Bensberg, DE
• Anton Kraus · Leichlingen, DE

Key dates

• Filing date: Nov 2, 1987
• Grant date: Feb 13, 1990
• Expiry date: Nov 2, 2007

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L1/242
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A device for measuring minute elongations of a light wave conductor is constructed as a light wave conductor-type sensing unit assembled of a series connection of a polarizer, a light coupler, a single polarization preserving, doubly refracting monomode light wave conductor enclosed in an elliptical sheathing and an analyzer. A light beam emitted from a laser diode is coupled via a light wave conducting correction cable to the polarizer and upon passage through the sensing unit is coupled via the light wave conducting connection cable to an optoelectric receiver and the electrical signals are evaluated in an electronic circuit. Changes in phase difference of the exiting light wave resulting from the minute changes in length of the light wave conductor are evaluated and scaled as geometric length units.