Fay, Sharpe, Beall, Fagan, Minnich & McKee
Plasma analyzer for trace element analysis
 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. 
Hitachi, Ltd.
G
G01N
inventional
Yukio Masamichi Masatoshi Takashi Hiromi Satoshi
Okamoto Tsukada Kitagawa Iino Yamashita Shimura