The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 22, 1987
Filed:
Nov. 24, 1986
Fumio Watanabe, Fukushima, JP;
Shojiro Komaki, Tokyo, JP;
Masao Miyamoto, Tokyo, JP;
Takao Ito, Tokyo, JP;
Seiko Instruments & Electronics Ltd., Tokyo, JP;
Abstract
A quadrupole mass spectrometer generates a stream of ionized particles which are modulated by an AC voltage and transmitted through a quadrupole analyzer to a detection unit. The detection unit detects at a collector electrode thereof a modulated ion current which is fed to a phase detector. The phase detector synchronizes the modulated ion current with a signal of known frequency to produce a DC voltage representative of the level of the modulated ion current. By modulating the ionized particles with the AC voltage, the S/N ratio is improved and adverse effects of external noise are diminished.