(19)

(11)

EP 0 267 956 A1

(12)

(43) Date of publication: 25.05.1988 Bulletin 1988/21 (21) Application number: 87903960.0 (22) Date of filing: 29.05.1987

(51) International Patent Classification (IPC):  G01B 11/ 16( . ) G01M 3/ 38( . ) G01F 1/ 66( . ) G01N 21/ 41( . ) (86) International application number: PCT/US1987/001279 (87) International publication number: WO 1987/007383 (03.12.1987 Gazette 1987/27)

(84) Designated Contracting States: DE FR GB (30) Priority: 30.05.1986 US 19860868736 (71) Applicant: DIFFRACTO, LTD. Detroit, MI 48098 (US)	(72) Inventors: CLARKE, Donald, A. Windsor, Ontario N8T 1J9 (CA) REYNOLDS, Roger Windsor, Ontario N8T 1J9 (CA) PRYOR, Timothy, R. Windsor, Ontario N8T 1J9 (CA) (74) Representative: Leine, Sigurd, Dipl.-Ing., et al  LEINE & KÖNIG Patentanwälte Burckhardtstrasse 1 D-30163 Hannover D-30163 Hannover (DE)