Patent · US Expired

Plasma analyzer for trace element analysis

US5130537A · kind A · utility

4Cited by
4References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 25, 1991
Grant dateJul 14, 1992
Priority date
Expiry dateMar 25, 2011

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N21/73
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A plasma analyzer for trace element analysis has a gas supply system comprising a plurality of gas sources, an electromagnetic valve provided on a line connecting each gas source to a plasma generating space, a buffer tank provided after the electromagnetic valve on the line, and a flow regulating flowmeter provided after the buffer tank on the line. Each electromagnetic valves is controlled for on-off operation and the corresponding buffer tank suppresses the sudden change of the flow rate of the corresponding gas, so that the composition of the gas supplied to the plasma generating space changes gradually in spite of the simple on-off operation of the electromagnetic valves. Thus, the fluctuation and extinction of the plasma attributable to the sudden change of the composition of the gas supplied to the plasma generating space can be effectively prevented.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.