impervious to air. to make impervious to air.
- Air pump
an apparatus for drawing in, compressing, or exhausting air. (initial capital letters) Astronomy. the constellation Antlia. Historical Examples Either the air pump or steam may be employed to create a partial void in the receiver beneath the filter. A Dictionary of Arts, Manufactures and Mines Andrew Ure Now place this apparatus under the receiver of […]
- Air quality
noun a measurement of the pollutants in the air; a description of healthiness and safety of the atmosphere Examples Smog is a mixture of pollutants, principally ground-level ozone and produced by chemical reactions, that greatly affects air quality. Contemporary Examples That sharp dip in air quality across the nation Sunday night? The ‘Reign’ Steamy Stairwell […]
- Air quality index
air quality index A measure of the quantity of harmful particles and chemicals in the air. Note: The index is used by weather forecasters to indicate the purity of the air on a given day. The higher the index, the smoggier (see smog) and more polluted the air. Contemporary Examples By comparison, New York’s air […]