(19)

(11)

EP 0 991 949 A1

(12)

(43) Date of publication: 12.04.2000 Bulletin 2000/15 (21) Application number: 98928328.8 (22) Date of filing: 20.05.1998

(51) International Patent Classification (IPC)7: G01R 11/04, H05K 7/14 (86) International application number: PCT/EP9803/165 (87) International publication number: WO 9857/185 (17.12.1998 Gazette 1998/50)

(84) Designated Contracting States: AT DE DK ES FI FR GR NL PT SE (30) Priority: 11.06.1997 GB 9712157 (71) Applicant: SCHLUMBERGER INDUSTRIES LIMITED London, WC2B 6XH (GB)	(72) Inventors: SLATOR, Kevin Felixstowne IP11 8XX (GB) GOLDING, Bruce KesgraveSuffolk IP5 2GF (GB) BOND, William Suffolk IP11 9HG (GB) (74) Representative: Montelmacher, Pascal (FR)  Schlumberger RMS50, avenue Jean Jaurès 92542 Montrouge Cedex 92542 Montrouge Cedex (FR)