Definition

1. Noun:
   • A unit of pressure: The standard atmosphere is a defined unit of pressure equal to the pressure that will support a column of mercury 760 millimeters high at sea level at a temperature of 0 degrees Celsius. It is used as a reference pressure in scientific and engineering fields.

Usage

• The term "standard atmosphere" is used as a fixed reference point for pressure measurements.
• It is often abbreviated as "atm" (e.g., 1 atm, 2.5 atm).
• It is primarily used in physics, chemistry, meteorology, and engineering contexts.

Examples

• Noun:
  • The pressure at sea level is approximately one standard atmosphere.
  • The experiment requires the chamber to be pressurized to three standard atmospheres.
  • One standard atmosphere is equivalent to 101,325 pascals.

Advanced Usage

• "Standard atmosphere" as a reference model: In atmospheric sciences, "Standard Atmosphere" (often capitalized) can also refer to a standardized model of how atmospheric pressure, temperature, and density change with altitude. The context usually clarifies the meaning.
  • The International Standard Atmosphere model is used for aircraft performance calculations.

Variants and Related Words

• Atmosphere (atm) (n): The common abbreviation for the unit "standard atmosphere."
  • The tire is inflated to 2.2 atm.
• Atmospheric pressure (n): The pressure exerted by the weight of the atmosphere, often measured in standard atmospheres.
  • The current atmospheric pressure is 1.01 standard atmospheres.

Synonyms

• atm: The direct abbreviation and synonym for the unit.
• Normal pressure: A less technical term sometimes used to refer to the standard atmospheric pressure at sea level.

Related Phrases

• Above atmospheric pressure: Refers to pressures greater than one standard atmosphere.
  • The gas is stored at ten times atmospheric pressure.
• Below atmospheric pressure: Refers to pressures less than one standard atmosphere, often called a vacuum or partial vacuum.
  • The pump can create a pressure well below one standard atmosphere.

Noun

1. a unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade