(19)

(11)

EP 1 828 812 A1

(12)

(43) Date of publication: 05.09.2007 Bulletin 2007/36 (21) Application number: 05822873.5 (22) Date of filing: 23.12.2005

(51) International Patent Classification (IPC):  G01W 1/14(2006.01) G01N 15/02(2006.01) G01P 3/68(2006.01) (86) International application number: PCT/GB2005/005088 (87) International publication number: WO 2006/067513 (29.06.2006 Gazette 2006/26)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR (30) Priority: 24.12.2004 GB 0428333 (71) Applicant: Campbell Scientific Limited Shepshed, Loughborough Leics LE12 9RP (GB)	(72) Inventors: ELLIS, Richard Loughborough Leicestershire LE12 9RP (GB) COUPLAND, Jeremy Wolfson School Mech. & Manufac. Loughborough Leicestershire (GB) (74) Representative: Higgin, Paul  Swindell & Pearson 48 Friar Gate Derby DE1 1GY Derby DE1 1GY (GB)