ABSOLUTE TEMPERATURE SCALE, the scale of temperature based on thermodynamics (q.v.), also called the Kelvin Scale after Lord Kelvin (q.v.). The temperature scale derived from the law of expansion of a perfect gas (q.v.), is iden tical with this thermodynamical scale. The usual abbreviations for absolute scale are abs., A, or K. Comparing it (approxi mately) with the centigrade scale (q.v.), o° C = 273° A, oo° C A, thus absolute zero is equivalent to —273° C. (See THERMODYNAMICS and THERMOMETRY.)