Air quality indicator
US9833734B2 · kind B2 · utility
14Cited by
49References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 3, 2014 |
| Grant date | Dec 5, 2017 |
| Priority date | — |
| Expiry date | Dec 3, 2034 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B30/70
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An air quality indicator for indicating high fine particle levels in an environment of interest. The indicator includes a frame maintaining first and second air filter media. The first air filter medium differs from the second air filter medium at least in terms of a change in visual appearance (e.g., color) when subjected to air flow containing fine particles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.