standard atmosphere: Meaning and Definition of

stand'ard at'mosphere

1. an arbitrarily determined vertical distribution of atmospheric pressure, temperature, and density, assumed to have physical constants and conforming to parametric equations, used for calculations in ballistics, the design of pressure altimeters, etc.
2. a standard unit of atmospheric pressure, having a value of 1013.2 millibars or 29.9213 in. (760 mm) of mercury.