US3783697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of determining small surface areas
Assignee: Quantachrome Corp
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Filing: 1972-06-20
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Granted: 1974-01-08
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Expires: 1992-06-20
Abstract
Abstract As an improvement over the method of U.S. Pat. No. 3,555,912 which uses flowing mixtures of adsorbate and inert diluent gases to develop surface measurement data, the within improved method further advances this technique by utilizing a cell, which contains the powder sample being measured, of an appropriate design to overcome errors which are found when low surface areas are measured. One optimum consequence using the improved cell hereof is that the measuring gaseous mixture is forced through the mass of the powder sample, thus controllably confining the surface area thereof being measured to the surface bounding the internal voids of the powder sample.
Inventors
- 👤 S Lowell
- 👤 S Karp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:12
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/08; G01N15/088; G01N15/0893
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
178 words
For a material having a first external surface and internal voids bounded by a second internal surface, a method of determining the surface areas of said material during which an adsorbate and an inert gaseous diluent are passed in adsorbing contact with said material, the improvement to said method comprising the steps of establishing a flow passage having a reversal in direction for said adsorbate and inert gaseous diluent with U-shaped wall means bounding a selected volume, filling said U-shaped flow passage with a quantity of said material which entirely occupies said selected flow passage volune such that there is surface contact between said material and said bounding wall means, and flowing said adsorbate and inert gaseous diluent through the mass of said material filling said U-shaped flow passage to establish said adsorbing contact only with said second internal surface arEa of said material bounding said internal voids, whereby surface area measurement is confined to that of said second internal surface to the exclusion of said first internal surface to thereby minimize errors in measuring small surface areas.
Claim 2
Dependent Claim
178 words
For a material having a first external surface and internal voids bounded by a second internal surface, a method of determining the surface areas of said material during which an adsorbate and an inert gaseous diluent are passed in adsorbing contact with said material, the improvement to said method comprising the steps of establishing a flow passage having a reversal in direction for said adsorbate and inert gaseous diluent with U-shaped wall means bounding a selected volume, filling said U-shaped flow passage with a quantity of said material which entirely occupies said selected flow passage volune such that there is surface contact between said material and said bounding wall means, and flowing said adsorbate and inert gaseous diluent through the mass of said material filling said U-shaped flow passage to establish said adsorbing contact only with said second internal surface arEa of said material bounding said internal voids, whereby surface area measurement is confined to that of said second internal surface to the exclusion of said first internal surface to thereby minimize errors in measuring small surface areas.
Claim 3
Dependent Claim
21 words
The improved method of determining surface area as defined in claim 1 wherein the flow passage is circular in cross section.
References Cited (Backward Citations)
US2960870A
Cited
US3211006A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |