Critical orifice dilution system and method
US5261452A · kind A · utility
19Cited by
9References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1992 |
| Grant date | Nov 16, 1993 |
| Priority date | — |
| Expiry date | Mar 27, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/87684
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus and method are provided for preparing low concentration gas phase calibration standards. The flows of a standard mixture of impurity in a gas and a dilution gas are controlled by regulating the pressure upstream of respective calibrated orifices. The pressures of the gas flows are regulated such that a critical flow condition is maintained through the orifices. The two flows are then combined to obtain a known dilution of the impurity in the gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.