Particle measuring system with pump adapted to maintain constant flow for different pressures and viscosities
US5410403A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 12, 1993 |
| Grant date | Apr 25, 1995 |
| Priority date | — |
| Expiry date | Aug 12, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N15/1404
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a particle measuring instrument for measuring particles entrained in liquids, a gear pump located downstream from the flow cell of the particle measuring instrument is used to maintain a constant rate of flow through the flow cell. When the source of liquid is at a high pressure, a pressure regulator and a check valve are used to maintain the pressures at the inlet and outlet sides of the gear pump, respectively, at predetermined pressure values to maintain a predetermined pressure differential across the gear pump. When the source of liquid to be measured is at ambient pressure, the outlet of the gear pump is connected to ambient pressure and the gear pump draws liquid through the flow cell causing the pressure at the inlet side of the gear pump to drop the predetermined pressure differential below ambient pressure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.