Electrodynamic transducer head

US5050703A · kind A · utility

Assignee

• Mannesmann AG · DE

Inventors

• Alfred Graff · Essen, DE
• Friedhelm Schlawne · Kerpen, DE
• Michael Wachter · Lankau, DE
• Wolfgang Bottger · Ködnitz, DE

Key dates

• Filing date: Oct 5, 1989
• Grant date: Sep 24, 1991
• Expiry date: Oct 5, 2009

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2291/0427
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention furnishes an electrodynamic transducer head for a non-destructive testing of workpieces with electrically conductive surfaces by way of ultrasound. A magnet system is employed for generating of a static or a low-frequency magnet field, and at least one transducer coil is disposed at the front face of the magnet system disposed toward the workpiece. The transducer coil is furnished on the side toward the workpiece with a wear-resistant layer, and the transducer coil exhibits between itself and this front face of the magnet system an intermediate part with an insulating layer, which is solidly connected with the front face and with the coil adjoining at the insulating layer. The invention discloses production of a transducer coil, in a way which is simple and economical and results in a transducer head which can be universally employed, and where the eddy current formations, resulting in interfering signals, and the mechanical vibrations, both in the transducer coil as well as in the magnet system, are substantially suppressed or, respectively, damped. The intermediate part (10) comprises at least two layers (11, 12), where one of the layers (12) is electrically conduct…