(19)

(11)

EP 0 053 613 A1

(12)

(43) Date of publication: 16.06.1982 Bulletin 1982/24 (21) Application number: 81901304.0 (22) Date of filing: 26.05.1981

(51) International Patent Classification (IPC):  G01B 11/ 02( . ) G01C 15/ 00( . ) G01B 11/ 16( . ) G01P 13/ 00( . ) (86) International application number: PCT/GB1981/000093 (87) International publication number: WO 1981/003698 (24.12.1981 Gazette 1981/30)

(84) Designated Contracting States: CH DE FR GB LI NL SE (30) Priority: 12.06.1980 GB 19800019248 (71) Applicant: BRYAN, William Edward Caithness KW1 4JJ (GB)	(72) Inventor: BRYAN, William Edward Caithness KW1 4JJ (GB) (74) Representative: Wotherspoon, Graham, et al  FITZPATRICKS 4 West Regent Street Glasgow G2 1RS Scotland Glasgow G2 1RS Scotland (GB)