A measured unit that is used as the basis for measuring other things; for example, a foot and a meter are standards of length.

Establishing a specific income level for a given-sized household below which the household is judged to be living in a state of poverty.

In physics, a unit of pressure equal to 760 torr, 1013.25 millibars, or 1.01325 x 10⁵ newtons per square meter (the terms used here are located in this unit).

The actual pressure exerted by he atmosphere fluctuates around this value, which is assumed to be standard at sea level and zero degrees centigrade/32 degrees Fahrenheit, and is used when dealing with very high pressures.

By James C. Fernald, L.H.D.; Funk & Wagnalls; New York; 1947.

A fixed set of conditions (including meteorological) to which the electrical performance data of a photovoltaic module are translated from the set of actual test conditions.

Conditions under which a module is typically tested in a laboratory.