Atmosphere (unit) for the purposes of specifying the physical properties of substances, “"standard pressure"” should be precisely . A pressure of 1 atm can also be stated as: Scuba divers and others use the word "atmosphere" and "atm" in relation to pressures that are relative to mean atmospheric pressure at sea level (1.013 bar). For example, a partial pressure of oxygen is calibrated typically using air at sea level, so is expressed in units of atm. The old European unit technical atmosphere (at) is equal to 1 kilogram-force per square centimetre (kgf/cm), Pa. Atmosphere (unit) The standard atmosphere (symbol: atm) is a
ALCO PA display in the museum. Unit DH-17 (former D&H #17) was painted in the classic Southern Pacific Daylight colors, but as of February 2010 had been painted over in primer. Algoma Central 78 is the former Denver and Rio Grande PB-1 6002. It was converted to a steam generator car in October 1965. It gained Blomberg B trucks in 1980. It was sold to Ansco in late 1987 for service on the Ski Train. It was sold again in 2007 to the Algoma Central. ALCO PA ALCO PA refers to a family of A1A-A1A diesel locomotives built to haul passenger trains