(19)

(11)

EP 0 764 264 A2

(12)

(43) Date of publication: 26.03.1997 Bulletin 1997/13 (21) Application number: 95902508.0 (22) Date of filing: 09.11.1994

(51) International Patent Classification (IPC):  G01N 1/ 28( . ) H01J 49/ 16( . ) H01J 49/ 04( . ) (86) International application number: PCT/US1994/012963 (87) International publication number: WO 1995/015001 (01.06.1995 Gazette 1995/23)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE (30) Priority: 12.11.1993 US 19930151490 (71) Applicants: Waters Corporation Milford, MA 01757 (US) Jarrell, Joseph A. Newton Highlands, MA 02161 (US) Tomany, Michael J. Thompson, CT 06277 (US) Dorschel, Craig A. Worcester, MA 01606 (US)	(72) Inventors: JARRELL, Joseph, A. Newton Highlands, MA 02161 (US) TOMANY, Michael, J. Thompson, CT 06277 (US) DORSCHEL, Craig, A. Worcester, MA 01606 (US) (74) Representative: Henkel, Feiler, Hänzel & Partner  Möhlstrasse 37 81675 München 81675 München (DE)