Patent · US Expired

Apparatus for testing documents having magnetic properties

US5457382A · kind A · utility

19Cited by
5References
16Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 16, 1992
Grant dateOct 10, 1995
Priority date
Expiry dateDec 16, 2012

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01V3/081
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

In an apparatus for testing test objects equipped with magnetic properties, the magnetic circuit with an air gap having a detector consists of at least a soft-magnetic material and a permanent-magnetic material, whereby the static magnetic field produced by the permanent-magnetic material penetrates the magnetic circuit. The air gap is preferably formed between an end of the soft-magnetic material and a pole of the permanent-magnetic material.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.