| 摘要 |
<p>As a control parameter given to a direct-current (DC) voltage generator (53) which generates a DC voltage for ion selection, a "mass-related offset" for allowing an adjustment of the offset for each mass-to-charge ratio is provided in addition to the "gain" and "common offset" which respectively determine the gradient and position of a scan line drawn on a stability diagram during a mass-scan operation. In an automatic adjustment operation using a standard sample, under the control of an automatic regulator (61), the "gain" and "common offset" are initially set, after which the "mass-related offset" for each mass-resolving power is determined so that the mass-resolving power will be substantially uniform, and these data are stored in a control data memory (52). In an analysis of a sample of interest, a quadrupole voltage controller (51) controls the DC voltage generator (53) and a radio-frequency (RF) voltage generator (54) according to the control parameters read from the memory (52). Even when the RF voltage V is non-linear due to the non-linearity of a wave-detector (56), the mass-resolving power can be made to be substantially uniform by varying the DC voltage U in the form of a polygonal line that resembles that non-linearity.</p> |
