| 摘要 |
PURPOSE:To suppress the peak shift quantity of a crest value and to determine the upper-limit and lower-limit values of a pulse height analyzer automatically by utilizing the counted value of detection pulses when an applied voltage is varied stepwise. CONSTITUTION:While the gain of a proportional amplifier is held at a constant level close to the maximum range, an applied high voltage control means (a) outputs a control signal to vary stepwise the high voltage applied from a high voltage generator to an X-ray detector. At this time, a peak detecting means (b) detects the maximum value of the counted value of detection pulses counted by a counter. A signal output means (c) fixes the applied voltage with which the X-ray detector has its maximum value. The measurement mode of a differential curve is entered and the upper-limit and lower-limit values of the crest value analyzer are determined according to the differential curve. Consequently, the peak shift quantity of the crest value is suppressed and the upper-limit and lower-limit values are determined automatically. |
