(19)

(11)

EP 0 105 875 A1

(12)

(43) Date of publication: 25.04.1984 Bulletin 1984/17 (21) Application number: 82901693.0 (22) Date of filing: 21.04.1982

(51) International Patent Classification (IPC):  G01F 1/ 66( . ) (86) International application number: PCT/US1982/000502 (87) International publication number: WO 1983/003897 (10.11.1983 Gazette 1983/26)

(84) Designated Contracting States: DE FR NL (71) Applicant: BESTOBELL SPARLING LIMITED Sussex RH15 9LL (GB)	(72) Inventors: BROWN, Alvin E. Santa Cruz, CA 94060 (US) JOHNSON, Rodney C. Sussex BN9 8DD (GB)