초록 ▼

In particle counting apparatus such as a hematology parameter measurement apparatus for performing multiple measurements on one blood sample, first and second impedance transducers, each including inner and outer electrodes, are provided for selective hydraulic connection to a probe head including o

In particle counting apparatus such as a hematology parameter measurement apparatus for performing multiple measurements on one blood sample, first and second impedance transducers, each including inner and outer electrodes, are provided for selective hydraulic connection to a probe head including one set of pressure ports and a further inner electrode. The first and second transducers are respectively immersed in first and second dilutions of the sample. Measurements on each dilution are made in a conventional manner. The inner electrodes are connected in parallel as are the outer electrodes so that small liquid passageways may be provided between the transducers and the probe head while maintaining a low impedance in the liquid path. Means are provided for selecting the sequence of operations and are provided to increase the throughput of samples for which multiple measurements are made.

대표청구항 ▼

In a particle counting apparatus of the impedance sensing type for counting particles passing in a liquid through an aperture by measuring the impedance between inner and outer electrodes on opposite sides of the aperture in the liquid path, including a transducer probe incorporating said aperture a

In a particle counting apparatus of the impedance sensing type for counting particles passing in a liquid through an aperture by measuring the impedance between inner and outer electrodes on opposite sides of the aperture in the liquid path, including a transducer probe incorporating said aperture and a volumetric metering chamber for metering a predetermined volume of liquid in connection with counting particles, the improvement comprising a conduit system disposed between said transducer probe and said metering chamber in the fluid path, the cross section of the conduit system being of a dimension such that bubbles which can be formed therein are small with respect to the predetermined volume of liquid to be metered by said volumetric metering chamber, and wherein said inner electrode comprises a first impedance measuring inner electrode on that side of the conduit system proximate said transducer probe and a second impedance measuring inner electrode disposed on that side of the conduit system proximate said volumetric metering chamber, said first and second inner electrodes being connected in parallel.