(19)

(11)

EP 0 660 933 A1

(12)

(43) Date of publication: 05.07.1995 Bulletin 1995/27 (21) Application number: 93920969.0 (22) Date of filing: 17.09.1993

(51) International Patent Classification (IPC):  G01N 33/ 543( . ) G01N 33/ 58( . ) (86) International application number: PCT/GB1993/001972 (87) International publication number: WO 1994/007140 (31.03.1994 Gazette 1994/08)

(84) Designated Contracting States: DE FR (30) Priority: 18.09.1992 GB 19920019743 01.10.1992 GB 19920020722 14.10.1992 GB 19920021578 27.11.1992 GB 19920024897 02.08.1993 GB 19930015991 02.08.1993 GB 19930015995 (71) Applicant: GEC-MARCONI LIMITED Stanmore, Middlesex HA7 4LY (GB)	(72) Inventor: ABUKNESHA, Ramadan, A. 16 Burgess Park Mansions London NW6 1DP (GB) (74) Representative: Cockayne, Gillian  GEC Patent Department Waterhouse Lane Chelmsford, Essex CM1 2QX Chelmsford, Essex CM1 2QX (GB)