(19)

(11)

EP 1 856 491 A2

(12)

(88) Date of publication A3: 09.11.2006 (43) Date of publication: 21.11.2007 Bulletin 2007/47 (21) Application number: 06736745.8 (22) Date of filing: 02.03.2006

(51) International Patent Classification (IPC):  G01G 21/28(2006.01) (86) International application number: PCT/US2006/007478 (87) International publication number: WO 2006/098893 (21.09.2006 Gazette 2006/38)

(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: 09.03.2005 US 75559 15.03.2005 US 80048 (71) Applicant: Metro Corporation Las Cruces, New Mexico 88001 (US)	(72) Inventor: WILLIAMSON, Sidney, W. Las Cruces, New Mexico 88005 (US) (74) Representative: Miller, James Lionel Woolverton et al Kilburn & Strode, 20 Red Lion Street London WC1R 4PJ London WC1R 4PJ (GB)