(19)

(11)

EP 2 260 279 A2

(12)

(88) Date of publication A3: 23.12.2009 (43) Date of publication: 15.12.2010 Bulletin 2010/50 (21) Application number: 09714465.3 (22) Date of filing: 04.02.2009

(51) International Patent Classification (IPC):  G01L 5/16(2006.01) (86) International application number: PCT/EP2009/051213 (87) International publication number: WO 2009/106407 (03.09.2009 Gazette 2009/36)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR Designated Extension States: AL BA RS (30) Priority: 28.02.2008 US 64334 (71) Applicant: ABB Technology AB 721 83 Västerås (SE)	(72) Inventor: BROGÅRDH, Torgny S-724 76 Västerås (SE) (74) Representative: Johansson Webjörn, Ingmari  ABB AB Intellectual Property Ingenjör Bååths Gata 11 721 83 Västerås 721 83 Västerås (SE)