(19)

(11)

EP 0 547 122 A1

(12)

(43) Date of publication: 23.06.1993 Bulletin 1993/25 (21) Application number: 91916286.0 (22) Date of filing: 04.09.1991

(51) International Patent Classification (IPC):  A01G 25/ 16( . ) G01N 33/ 24( . ) (86) International application number: PCT/GB1991/001497 (87) International publication number: WO 1992/003916 (19.03.1992 Gazette 1992/07)

(84) Designated Contracting States: DE FR GB IT (30) Priority: 05.09.1990 GB 19900019377 (71) Applicant: BRITISH TECHNOLOGY GROUP LTD London SE1 6BU (GB)	(72) Inventor: HETTIARATCHI, Daniel Rabindranath Parakrama Gosforth, Newcastle-upon-Tyne NE3 5DX (GB) (74) Representative: Trevor-Briscoe, David William  Patents Department British Technology Group Ltd 101 Newington Causeway London SE1 6BU London SE1 6BU (GB)