Insulating tube surrouding anode tube in analytical glow discharge tube
AssigneeShimadzu Corporation
InventorsTakao Miyama, Tanaka Shoichi, Fukui Isao
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Abstract
A glow discharge tube for exciting a sample in emission spectrochemical analysis or mass spectrometry, in which glow discharge is effected between the anode tube and the sample while gas is being passed, for exhaust, through the narrow gap formed between the sample surface and the end of the insulating tube fit on the anode tube so as to maintain a constant pressure in the anode tube. Since the insulating tube projects further than the anode tube toward the sample side, a shortcircuit is never formed between the anode and the cathode even if sample vapor adheres to the walls surrounding the exhaust passage. As a result, efficient analysis can be achieved with the glow discharge tube of the present invention.
Claims4
An analytical glow discharge tube in which a sample as a cathode is placed facing an anode tube end with a specified discharge gap therebetween, and wherein gas in the discharge gap is directed to the outer side of the anode tube so as to be exhausted, said discharge tube comprising:
- an insulating tube disposed around said anode tube and spaced apart from said sample, an end of said insulating tube projecting beyond said anode tube end toward said sample such that said gas is exhausted around the outer circumferences of said insulating tube, and wherein an exhaust passage, for said exhaust gas flowing in the discharge region between the anode and the cathode, has a width narrower than said discharge gap.
Dependencies are inferred from the claim text.