(19)

(11)

EP 0 861 414 A1

(12)

(43) Date of publication: 02.09.1998 Bulletin 1998/36 (21) Application number: 96938338.0 (22) Date of filing: 11.11.1996

(51) International Patent Classification (IPC):  G01B 21/ 14( . ) G01B 7/ 13( . ) G01B 5/ 12( . ) (86) International application number: PCT/GB1996/002782 (87) International publication number: WO 1997/018437 (22.05.1997 Gazette 1997/22)

(84) Designated Contracting States: AT BE CH DE DK ES FI FR GB GR IE IT LI NL PT SE (30) Priority: 15.11.1995 GB 19950023323 (71) Applicant: System E Controls Limited Leamington Spa Warwickshire CV32 5AN (GB)	(72) Inventors: MOWATT, James, Stanley Essex RM2 5NS (GB) BURTON, Barrie, Charles Rugby CV23 8JP (GB) (74) Representative: Lawrence, John  Barker Brettell 138 Hagley Road Edgbaston Birmingham B16 9PW Birmingham B16 9PW (GB)