| 摘要 |
An apparatus for detecting corpuscles such as blood cells. The apparatus has an aperture and a constant-current source that supplies an electrical current to the aperture for detection of corpuscles. When corpuscles to be investigated pass through the aperture, the electrical impedance changes, producing a signal (herein referred to as the corpuscle signal). The apparatus further includes a pseudo signal-generating means producing a pseudo signal in the form of pulses. The pseudo signal has a peak value proportional to the amplitude of the input current and is equivalent to the corpuscle signal detected when the corpuscles pass through the aperture. A signal selector means is disposed among the aperture, the constant-current source, and the pseudo signal-generating means. The signal selector means assumes either a first state or a second state. In the first state, the current from the power supply is supplied to the pseudo signal-generating means, and the pseudo signal produced by the pseudo signal-generating means is supplied to the aperture. In the second state, the current from the power supply is supplied to the aperture.
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