Patent Yard Sign in
Expired European patentEurope

Improvements in the measurement of impedance ratios

EP 0159786 B1 · Applicant: AUTOMATIC SYSTEMS LABORATORIES LIMITED

EPO PDF

Overview

The published document from the EPO: abstract, claims, description and drawings. Open it full size

Read the whole patent

Listed from its EPO record in Patent Yard's archive of European patents past their term. Its claims, description and drawings are in the EPO PDF and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Filed March 7, 1985 and granted November 2, 1988. A European patent lasts at most 20 years from filing, so its term ended March 7, 2005.
  • A supplementary protection certificate, which can extend a medicine or crop-protection patent, adds at most five and a half years, so even that would have ended by September 7, 2010.
  • We check European rights only. A US or other national patent in its family could still be in force: check its family on Espacenet or Google Patents.
FiledMarch 7, 1985
PublishedOctober 30, 1985
GrantedNovember 2, 1988
Term endedMarch 7, 2005
Application numberEP 85301562
Classification (CPC)G01R19/10 +1 more

Timeline

Timeline From EPO dates

1986198819901992199419961998200020022004Application filedMarch 7, 1985PublishedOct 30, 1985Patent grantedNov 2, 1988Term endedMarch 7, 2005

Sources & verification