(19)

(11)

EP 1 941 248 A1

(12)

(43) Date of publication: 09.07.2008 Bulletin 2008/28 (21) Application number: 06794815.8 (22) Date of filing: 19.10.2006

(51) International Patent Classification (IPC):  G01F 23/28(2006.01) (86) International application number: PCT/GB2006/003874 (87) International publication number: WO 2007/049005 (03.05.2007 Gazette 2007/18)

(84) Designated Contracting States: DE FR GB IT (30) Priority: 26.10.2005 GB 0521800 (71) Applicant: TRW Limited Solihull, West Midlands B90 4AX (GB)	(72) Inventors: HAZELDEN, Roger, John Staffordshire B77 4PL (GB) PINNOCK, Robert Andrew Birmingham B30 2DN (GB) (74) Representative: Tranter, Andrew David  Barker Brettell LLP 138 Hagley Road Esgbaston Birmingham B16 9PW Esgbaston Birmingham B16 9PW (GB)