(19)

(11)

EP 0 943 107 A1

(12)

(43) Date of publication: 22.09.1999 Bulletin 1999/38 (21) Application number: 97949015.0 (22) Date of filing: 09.12.1997

(51) International Patent Classification (IPC):  G01V 3/ 00( . ) G01V 15/ 00( . ) (86) International application number: PCT/GB1997/003389 (87) International publication number: WO 1998/026312 (18.06.1998 Gazette 1998/24)

(84) Designated Contracting States: AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE Designated Extension States: AL LT LV MK RO SI (30) Priority: 09.12.1996 GB 19960025561 (71) Applicant: Flying Null Limited Harston, Cambridge CB2 5NH (GB)	(72) Inventor: DAMES, Andrew, Nicholas Cambridge CB4 1HU (GB) (74) Representative: Abrams, Michael John  Haseltine Lake & Co., Imperial House, 15-19 Kingsway London WC2B 6UD London WC2B 6UD (GB)