Transducer for measuring particles suspended in a fluid

摘要

A transducer for measuring particles suspended in a fluid is disclosed. The transducer includes an elongated tubular member having a particle-free fluid conducting channel and an aperture for permitting the flow of a particle containing fluid into the fluid conducting channel. The size of the particles is measured by measuring the impedance variation of the particle containing fluid as it passes through the aperture. Spurious variations of the impedance caused by reentry of the particles into the region about the aperture is prevented by spacing the wall of the channel opposite the aperture so that the particle containing fluid impinges thereon after passing through the aperture and so that the particle-free fluid transports the particles away from the aperture before the particles reenter the region about the aperture.