Lesson plan
cascade impactor
A cascade impactor is an instrument used to sample, fractionate, and collect aerosol particles into discrete size classes based on their aerodynamic diameter. It operates on the principle of inertial impaction through a sequential series of stages. As an air or gas stream is drawn through progressively narrower nozzles, particle velocity increases; particles with sufficient inertia deviate from fluid streamlines to strike and deposit onto collection plates, while smaller particles remain suspended in the flow and proceed to downstream stages. Cascade impactors are standard tools in atmospheric chemistry, occupational hygiene, air pollution monitoring, and pharmaceutical testing, particularly for the determination of aerodynamic particle size distribution (APSD) in orally inhaled drug products such as metered-dose inhalers (MDIs) and dry-powder inhalers (DPIs).
Article summary
A cascade impactor is an instrument used to sample, fractionate, and collect aerosol particles into discrete size classes based on their aerodynamic diameter. It operates on the principle of inertial impaction through a sequential series of stages. As an air or gas stream is drawn through progressively narrower nozzles, particle velocity increases; particles with sufficient inertia deviate from fluid streamlines to strike and deposit onto collection plates, while smaller particles remain suspended in the flow and proceed to downstream stages. Cascade impactors are standard tools in atmospheric chemistry, occupational hygiene, air pollution monitoring, and pharmaceutical testing, particularly for the determination of aerodynamic particle size distribution (APSD) in orally inhaled drug products such as metered-dose inhalers (MDIs) and dry-powder inhalers (DPIs).
Key claims
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Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
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Key claims and bibliography are generated from the same tracked claims and sources as the article page.