Conical DC plasma emission source

US4630924A · kind A · utility

Assignee

• THE DOW CHEMICAL COMPANY · US

Inventor

• Gerhard Meyer · Erlangen, DE

Key dates

• Filing date: Jul 29, 1985
• Grant date: Dec 23, 1986
• Expiry date: Jul 29, 2005

Classification

• Technology area (CPC H): Electricity
• CPC primary: H05H1/42
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A DCP spectrometer emission source for creating a conical high temperature plasma through which an aerosol suspended sample is able to penetrate which generally includes at least three D.C. powered electrodes, a base structure for circumferentially spacing the electrodes about a central axis, and an introduction conduit associated with the central axis for injecting the aerosol sample stream into the conical shaped plasma created by the electrodes. The base structure circumferentially spaces the electrodes about the central axis such that the longitudinal axes of the electrodes converge radially toward the central axis at an acute angle to the central axis. Each of the electrodes has an electrode member and a conduit for conveying an ionizable gas passed the electrode members. The electrode members are also connected to a source of D.C. electrical power such that two of the electrode members have the same polarity and the third electrode member has the opposite polarity.