(19)

(11)

EP 0 090 818 A1

(12)

(43) Date of publication: 12.10.1983 Bulletin 1983/41 (21) Application number: 82902908.0 (22) Date of filing: 04.10.1982

(51) International Patent Classification (IPC):  G01B 5/ 00( . ) G01B 7/ 012( . ) G01B 7/ 00( . ) G01B 21/ 00( . ) (86) International application number: PCT/GB1982/000284 (87) International publication number: WO 1983/001301 (14.04.1983 Gazette 1983/09)

(84) Designated Contracting States: AT BE CH DE FR LI LU NL SE (30) Priority: 07.10.1981 GB 19810030300 (71) Applicant: BUTLER, Edwin Terry Nottingham (GB)	(72) Inventor: BUTLER, Edwin Terry Nottingham (GB) (74) Representative: Coxon, Philip, et al  Eric Potter & Clarkson St. Mary's Court St. Mary's Gate Nottingham NG1 1LE Nottingham NG1 1LE (GB)