Method and apparatus for improved flow and pressure measurement and control
US5524084A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1994 |
| Grant date | Jun 4, 1996 |
| Priority date | — |
| Expiry date | Dec 30, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2030/025
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In the preferred embodiment, the invention is embodied in the pneumatic manifold of a gas chromatograph to provide current operating temperature and pressure compensation of inlet fluid flow. The pneumatic manifold comprises a plurality of thermally coupled mass flow, pressure and temperature sensors which generate signals related to mass flow of the fluid, fluid pressure and sensor temperature prior to the introduction of the fluid into the column. A plurality of firmware models which characterize the effects of current operating temperature and pressure variations on the mass flow and pressure sensors are stored in computer memory. Compensation is provided by determining the desired flow into the inlet, determining the control signal required to achieve this values at current operating conditions, determine the current operating conditions, implementation of firmware models to determine the effects on flow due to changes in current operating conditions and finally, generation of an adjustment to the control signal that nullifies the effects caused by changes in current operating conditions. These steps are repeated continuously to provide closed loop control of the desired detect…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.