| 摘要 |
PURPOSE:To automate completely the compensation of the fluctuation of a pulse height value, by measuring only a pulse having a peak value within a reference peak region on the distribution of the height of a detection pulse, and by adjusting a gain of an amplifier based on the ratio of a measured value to a set value. CONSTITUTION:When a gain of a main amplifier 4 is set so that a pulse having a height value higher than that of a 241 Am alpha-ray pulse P is negligibly few, the values at a counting rate n3 of pulses having height values of H4 or above which are measured by a pulse-height discriminator 10 are determined primarily only by the relative position of H4 in relation to the distribution of height. When a pulse height value is controlled so that the counting rate n3 is equal to a value n30 to serve as a reference, a gain control can be automated completely even when the height value fluctuates sharply and when a power source of a measuring system is made. |
