In science, calorimeter, from the French calor- “heat” + -meter “measure”, is an instrument (see: thermodynamic instrument) that measures heat, e.g. reaction heat (see: reaction calorimeter), given off or absorbed by a substance, the substance typically confined to a chamber, which is surrounded by a body of water contained in a larger container, wherein a thermometer in the water measures the change in temperature, thus allowing for a calculation of the heat given off or absorbed, via use of the heat capacity of the water; a heat meter.

In 1782, Antoine Lavoisier and Pierre Laplace, using ideas on heat capacity, e.g. from Joseph Black, built the following calorimeter:

Lavoisier-Laplace calorimeter

In 1844, James Joule, in his “On the Changes of Temperature produced by the Rarefaction and Condensation of Air”, reported on two experiments, wherein he used two strong connecting copper vessels, and calorimeter, with double walls, designed to accommodate the two vessels, as shown below, wherein after evacuating one container, with an air pump (vacuum pump), leaving the other filled with gas, then opened the valve, and calculated the change in temperature in the water of the calorimeter: [1]

Joule experiment (1844)

He then repeated this experiment, but this time by putting each copper vessel in its own calorimeter, so to ascertain a unique temperature change for each:

Joule experiment 2

These two experiments enabled him to prove that when a “perfect gas” expands without doing work its “internal energy” remains unchanged.

In 1964, George Armstrong, in his “The Calorimeter and its Influence on the Development of Chemistry”, is said to give a cogent overview of the history of calorimetry, in respect to the invention of “ingenious instruments” developed over the years, following Lavoisier and Laplace. [3]

Social calorimeter
See: Human thermodynamic instrument
In 2007, Libb Thims, in his Human Chemistry, gave an overview as to how to go about constructing a human reaction calorimeter and human molecular or human system thermometers, so to be able to measure quantities such as human reaction enthalpy change. [2]

See also
● Reaction calorimeter

1. (a) Joule, James. (1844). “On the Changes of Temperature produced by the Rarefaction and Condensation of Air” (abstract) (by: Dr. Roget) (note: paper, supposedly was rejected by Royal Society), Proceedings of the Royal Society, Jun 20; published in: Philosophical Magazine, Series Three; May; both in: Scientific Papers, Volume One (pg. 171-89; quote, pg. 189). Publisher.
(b) Cardwell, Donald S.L. (1971). From Watt to Clausius: the Rise of Thermodynamics in the Early Industrial Age (pg. 235; image, plate 23). Cornell University Press.
2. (a) Thims, Libb. (2007). Human Chemistry (Volume Two) (human calorimeters, pgs. 431-330; proxemics, pgs. 550, 631). Morrisville, NC: LuLu.
(b) Thims, Libb. (2007). Human Chemistry (Volume One) (hot molecules and volume change, ch. 8: “Planck’s quantum, pgs. 213-245; proxemics, pgs. 225-; ch. 9: Human Molecular Orbitals, pgs. 247-95). Morrisville, NC: LuLu.
3. (a) Armstrong, George T. (1964). “The Calorimeter and its Influence on the Development of Chemistry” (Ѻ) (abs), Journal of Chemical Education, 41(6):287-.
(b) Edsall, John T. and Gutfreund, Hanoch (1983). Biothermodynamics: the Study of Biochemical Processes at Equilibrium (pg. 1). Wiley.

External links
Calorimeter – Wikipedia.

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