| 摘要 |
The pulses produced by a Coulter type of electronic particle analyzer having a scanning aperture have amplitudes proportional to the particle volumes; hence, random in amplitude. The pulses are variably asymmetric due to the particle scanning aperture and particle flow arrangement. The most reliable measure of particle volume is pulse amplitude at the time when the particle is halfway through the scanning aperture path. By attenuating each pulse to the same predetermined percentage of its amplitude and comparing the attenuated signal level with the original pulse in two different time spaced channels, there results two equal rectangular time-spaced pulses that separately then are integrated and compared. If the integration durations are equal, but one integral signal is attenuated to one half, then the two time-spaced integral signals will have equal amplitudes at the time center of the rectangular pulse, the symmetric time center of the original pulse. Adjustment of the slope of integration and/or attenuation of one integral signal can shift the time position. In this manner the amplitude of the particle-pulse can be strobed at its aperture path center time.
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