Porosity measuring apparatus and perforating system using same
US4246775A · kind A · utility
14Cited by
4References
24Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 8, 1979 |
| Grant date | Jan 27, 1981 |
| Priority date | — |
| Expiry date | Jun 8, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N15/0826
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Porosity measuring apparatus for a moving web of sheet material comprising a sensor having a chamber and a wall provided with apertures communicating with the chamber and of number, spacing and dimension sufficient to obtain an air seal between the moving web and wall during application of a vacuum to the chamber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.