(19)

(11)

EP 0 120 943 A1

(12)

(43) Date of publication: 10.10.1984 Bulletin 1984/41 (21) Application number: 83903441.0 (22) Date of filing: 24.09.1983

(51) International Patent Classification (IPC):  G01K 7/ 20( . ) (86) International application number: PCT/US1983/001487 (87) International publication number: WO 1984/001218 (29.03.1984 Gazette 1984/09)

(84) Designated Contracting States: CH DE FR GB LI NL SE (30) Priority: 24.09.1982 US 19820423281 (71) Applicant: NEIL BROWN INSTRUMENT SYSTEMS INC. Cataumet MA 02534 (US)	(72) Inventor: BROWN, Neil, L. Sharon, MA 02067 (US) (74) Representative: Smith, Philip Antony, et al  REDDIE & GROSE 16 Theobalds Road London WC1X 8PL London WC1X 8PL (GB)