QUADRUPOLE ELECTRODE APPLICATION VOLTAGE GENERATION CIRCUIT FOR QUADRUPOLE MASS SPECTROMETER

摘要

PROBLEM TO BE SOLVED: To detect a wave accurately even if a high frequency voltage is small, provide phase detection characteristic having the linear property over a wide range, and dispense with minute adjustment of a phase detection circuit every time a quadrupole mass spectrometer is used.;SOLUTION: A quadrupole electrode application high frequency voltage detected in a high frequency transformer 109 is heterodyne-detected by a frequency converter 12 and an ideal rectifier 16 through an attenuator 10 to generate a voltage indicating an envelope of an applied high frequency voltage. The ideal rectifier 16 is constituted by a combination of diodes and operation amplifiers to provide ideal rectification characteristic. In addition to the method, a system in which a phase of the applied high frequency voltage is synchronized with a phase of a high frequency signal having the same frequency as the frequency to multiply them by a multiplier in order to detect an envelope and a system in which the applied high frequency voltage is switched by the phase- synchronized high frequency signal having the same frequency as high frequency of the frequency to detect an envelope in an analog switch are disclosed.;COPYRIGHT: (C)2002,JPO