Method of continuous measurement of damping in an elongated light wave conductor-sensor having only one accessible end

US4943714A · kind A · utility

Assignee

• Felten & Guilleaume Energietechnik GmbH · DE

Inventors

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

Key dates

• Filing date: Feb 10, 1989
• Grant date: Jul 24, 1990
• Expiry date: Feb 10, 2009

Classification

• Technology area (CPC G): Physics
• CPC primary: G01M11/31
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

To enable a continuous measurement of damping of a light beam in light wave conductor (LWC)-sensor which is accessible at one end only, a measuring light beam emitted by a transmitter is guided through a light wave conductor into a beam divider in which a measuring partial light beam is guided in the same direction as the transmitted beam to a measuring LWC-sensor. At the free end of the sensor the measuring partial light beam is totally reflected to propagate in reverse direction back against the beam divider where it is deflected by 90.degree. and guided into a light receiving and measuring unit. The other partial light beam is employed either for the temperature compensation or for the compensation of the power output of the light transmitter or of sensitivity of the light receiver.