Defect detection

US4298808A · kind A · utility

Assignee

• British Steel Corporation

Inventor

• Walter Hill · Mettmann, DE

Key dates

• Filing date: Jan 8, 1979
• Grant date: Nov 3, 1981
• Expiry date: Jan 8, 1999

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2291/044
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method for indicating a defect in a workpiece, comprises applying a continuously variable signal derived from inspection of the workpiece and including a pulse component representative of the defect to a bank of filters having different frequency transmission characteristics respectively representative of defects of different type so that the filter corresponding most closely to the defect inspected, produces a relatively greater output and provides an indication of defect type.