Apparatus for the determination of surface cracks

US4759221A · kind A · utility

Assignee

• Kraftwerk Union Aktiengesellschaft · DE

Inventors

• Erhard Ortlieb · Kalchreuth, DE
• Peter Wahode · Neunkirchen, DE

Key dates

• Filing date: Mar 17, 1987
• Grant date: Jul 26, 1988
• Expiry date: Mar 17, 2007

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2291/02854
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An apparatus for determining the depth of cracks in the surfaces of workpieces includes an ultrasonic transducer for sending ultrasonic signals to and receiving ultrasonic signals from the workpiece, an analyzer connected to the ultrasonic transducer for forming a frequency spectrum from the ultrasonic signals, an evaluating unit connected to the analyzer for determining an effective band width correlated with the depth of the cracks in the workpiece as the quotient of the integral of the frequency spectrum and the ordinate value of the center of concentration of the integrated surface of the frequency spectrum, and an indicator connected to the evaluating unit for indicating the depth of the cracks.