(19)

(11)

EP 0 189 438 A1

(12)

(43) Date of publication: 06.08.1986 Bulletin 1986/32 (21) Application number: 85903094.0 (22) Date of filing: 15.05.1985

(51) International Patent Classification (IPC):  G01T 1/ 204( . ) G02F 1/ 13( . ) (86) International application number: PCT/US1985/000915 (87) International publication number: WO 1985/005459 (05.12.1985 Gazette 1985/26)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 21.05.1984 US 19840612179 (71) Applicant: BECKMAN INDUSTRIAL CORPORATION Fullerton California 92634 (US)	(72) Inventor: KEENAN, Charles, A. Irvine, CA 92664 (US) (74) Representative: Wotherspoon, Graham, et al  FITZPATRICKS 4 West Regent Street Glasgow G2 1RS Scotland Glasgow G2 1RS Scotland (GB)