(19)

(11)

EP 0 031 350 A1

(12)

(43) Date of publication: 08.07.1981 Bulletin 1981/27 (21) Application number: 80901235.0 (22) Date of filing: 25.06.1980

(51) International Patent Classification (IPC):  G01N 21/ 41( . ) (86) International application number: PCT/DK1980/000038 (87) International publication number: WO 1981/000152 (22.01.1981 Gazette 1981/02)

(84) Designated Contracting States: AT CH DE FR GB LI LU NL SE (30) Priority: 26.06.1979 DK 19790002706 (71) Applicant: A/S N. Foss Electric DK-3400 Hilleroed (DK)	(72) Inventor: AEGIDIUS, Poul Erik DK-3200 Helsinge (DK)