| 摘要 |
<p>An apparatus for studying particles of widely different sizes includes a vessel and a fluid medium in the vessel with the particles suspended thereon. First and second aperture tubes are suspended in the vessel at a first height, and a third aperture tube is suspended at a second lower height. The first aperture tube has an aperture of substantially smaller size than the second and third aperture tubes. The rate of entry through the aperture and into the second tube, of particles large enough to cause blockage of the first aperture in the first tube, is detected. When this rate drops below a first particular rate, indicating that substantially all particles greater than that size have settled below this particular height in the beaker, control circuitry is actuated to enable the fluid to enter into the first tube via the aperture therein for analyzing particles received therein via Coulter type detectors.</p> |
