Calorie

calorie

, calory

a unit of heat, equal to 4.1868 joules (International Table calorie): formerly defined as the quantity of heat required to raise the temperature of 1 gram of water by 1°C under standard conditions. It has now largely been replaced by the joule for scientific purposes

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Calorie

1. a unit of heat, equal to one thousand calories, often used to express the heat output of an organism or the energy value of food

2. the amount of a specific food capable of producing one thousand calories of energy

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

calorie

[′kal·ə·rē]

(thermodynamics)

Abbreviated cal; often designated c.

A unit of heat energy, equal to 4.1868 joules. Also known as International Table calorie (IT calorie).

A unit of energy, equal to the heat required to raise the temperature of 1 gram of water from 14.5° to 15.5°C at a constant pressure of 1 standard atmosphere; equal to 4.1855 ± 0.0005 joules. Also known as fifteen-degrees calorie; gram-calorie (g-cal); small calorie.

A unit of heat energy equal to 4.184 joules; used in thermochemistry. Also known as thermochemical calorie.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

calorie

The heat required to raise the temperature of 1 gram of water 1°C; now called a small calorie. A large calorie is equal to 1000 small calories, i.e. a kilocalorie.

McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Calorie

 

a unit of heat that is not part of a system of units. Designation, cal. In addition to the calorie, the kilocalorie (also known as the large calorie) is widely used; 1 kcal = 1,000 cal.

Originally, the calorie was defined as the quantity of heat necessary to raise the temperature of 1 g of water by 1°C. Neither the temperature interval within which the heating was performed nor its conditions had been defined prior to the late 19th century. Various calories have therefore been used: the 0°, 15°, 20°, and 25° calories as well as the average calorie and the thermochemical calorie. The 20° kilocalorie was used in the USSR from 1934 to 1957. This kilocalorie was equal to the quantity of heat (with an accuracy of up to 0.02 percent) required to heat 1 kg of water from 19.5° to 20.5°C.

The First International Steam Table Conference (London, 1929) introduced the international calorie, defined as 1/861.1 of the international kilowatt-hour (kW-hr). The InternationalSteam Table Conferences in 1954 and 1956 accepted the decisionon transition from the calorie to a new unit, the absolute joule(J), which subsequently was included in the International Sys-tem of Units. The following relationship was established betweenthe calorie and the joule: 1 cal = 4.1868 J (exactly). The 20°calorie is equal to 4.181 J. The calorie used widely in thermo-chemistry is equal to 4.1840 J.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.