| 摘要 |
A sensor for use with apparatus operating in accordance with the principles of the Coulter electronic particle studying device, for differentiating between pulses produced by particles passing on axial or nearly axial paths through an aperture and pulses produced by particles passing off center. The pulse duration is measured at some fraction of the individual pulse amplitudes and only those which meet the criteria of duration established by the electronic circuitry are permitted to pass for use in pulse height analysis apparatus following the sensor. The other pulses are discarded on the basis of their greater durations. The apparatus of the invention provides structure for deriving a duration-measuring pulse whose duration is that of the particle pulse at its fractional amplitude, converting the signal into one which has an amplitude proportional to duration, and then subjecting the latter signal to the criteria of duration established as amplitude levels to operate gating means automatically for rejecting the longer duration pulses and passing the shorter duration pulses.
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