| 摘要 |
PURPOSE:To correct the difference in mass by a mass defect and to obtain the spectrum coinciding with a mass number by providing a mass defect correction circuit to an electric circuit part for setting the mass of a mass filter and driving the mass filter by the corrected data. CONSTITUTION:The output of a mass number setting circuit 21 is added to the output of the mass defect correction circuit 22 and is then amplified by a high-frequency amplifier 24. The amplified output is supplied to the mass filter 25. The circuit 22 receives a mass number input signal from the circuit 21 and outputs a mass defect correction quantity signal and, therefore, the voltage impressed from an amplifier 24 to the mass filter 25 becomes the voltage in the curve (solid line) state curving slightly downward from a broken line state as shown by the solid line of the figure. The quadruple mass filter 25 is, therefore, used; in addition, an increase in the difference between the spectrum peak top and the mass number part to be measured and a consequent increase in measurement error are obviated even if there is the mass defect in actual ions and even if the impressed voltage and the mass number of the passing ions are not proportional. |
