(19)

(11)

EP 0 918 977 A1

(12)

(43) Date of publication: 02.06.1999 Bulletin 1999/22 (21) Application number: 98932261.0 (22) Date of filing: 16.06.1998

(51) International Patent Classification (IPC):  G01B 7/ 02( . ) G01B 7/ 14( . ) (86) International application number: PCT/GB1998/001749 (87) International publication number: WO 1998/058230 (23.12.1998 Gazette 1998/51)

(84) Designated Contracting States: DE FR GB IT NL (30) Priority: 18.06.1997 GB 19970012848 (71) Applicant: QUEENSGATE INSTRUMENTS LIMITED Bracknell, Berkshire, RG12 1RB (GB)	(72) Inventor: HICKS, Thomas, Rudolph London W4 3HR (GB) (74) Representative: Lupton, Frederick, et al  Kilburn & Strode, 20 Red Lion Street London WC1R 4PJ London WC1R 4PJ (GB)