Potential-sensing method and apparatus for sensing and characterizing particles by the Coulter principle
US6175227A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1998 |
| Grant date | Jan 16, 2001 |
| Priority date | — |
| Expiry date | Jul 1, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2015/135
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A Coulter apparatus comprises a volumeter assembly containing a conduit through which a particle suspension is caused to pass simultaneously with an electrical current. In preferred embodiments the volumeter assembly comprises at least one traditional Coulter conduit wafer, i.e., a dielectric wafer containing a central circular conduit, and at least two electrically conductive collars. The conductive collars approximate the conduit diameter in thickness, are uninsulated, and are attached to opposite sides of the conduit wafer, the openings being congruent with the Coulter conduit. The Coulter conduit in the dielectric wafer and the openings in the conductive collars collectively form a hydrodynamically smooth conduit, in which the electric and hydrodynamic fields of the Coulter conduit are amended. The electric field is shaped to confine the particle-sensitive zone of the novel volumeter conduit within the conduit's physical boundaries, thereby decreasing the zone's coincidence volume. The hydrodynamic field is caused to develop quasi-laminar flow, thereby increasing the proportion of particles per second transiting the zone's electrically homogeneous areas. The conductive collars …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.