Chronometry

Chronometry^[a] or horology^[b] (lit. 'the study of time') is the science studying the measurement of time and timekeeping.^[3] Chronometry enables the establishment of standard measurements of time, which have applications in a broad range of social and scientific areas. Horology usually refers specifically the study of mechanical timekeeping devices, while chronometry is broader in scope, also including biological behaviours with respect to time (biochronometry), as well as the dating of geological material (geochronometry).

Not to be confused with Chronology.

Horology is commonly used specifically with reference to the mechanical instruments created to keep time: clocks, watches, clockwork, sundials, hourglasses, clepsydras, timers, time recorders, marine chronometers, and atomic clocks are all examples of instruments used to measure time. People interested in horology are called horologists. That term is used both by people who deal professionally with timekeeping apparatuses, as well as enthusiasts and scholars of horology. Horology and horologists have numerous organizations, both professional associations and more scholarly societies. The largest horological membership organisation globally is the NAWCC, the National Association of Watch and Clock Collectors, which is US based, but also has local chapters elsewhere.

Records of timekeeping are attested during the Paleolithic, in the form of inscriptions made to mark the passing of lunar cycles and measure years. Written calendars were then invented, followed by mechanical devices. The highest levels of precision are presently achieved by atomic clocks, which are used to track the international standard second.^[4]^[5]

Time metrology[edit]

Time metrology or time and frequency metrology is the application of metrology for timekeeping, including frequency stability.^[28]^[29] Its main tasks are the realization of the second as the SI unit of measurement for time and the establishment of time standards and frequency standards as well as their dissemination.^[30]

– AWCI (United States of America)

American Watchmakers-Clockmakers Institute

– AHS (United Kingdom)

Antiquarian Horological Society

– BHI (United Kingdom)

British Horological Institute

(Switzerland)

Chronometrophilia

– DGC (Germany)

Deutsche Gesellschaft für Chronometrie

– HSNY (United States of America)

Horological Society of New York

– NAWCC (United States of America)

National Association of Watch and Clock Collectors

- UK Clock & Watch Company based in Bristol

UK Horology

Notable scholarly horological organizations include:

Complication (horology)

Hora (astrology)

List of clock manufacturers

List of watch manufacturers

Winthrop Kellogg Edey

Allan variance

Clock drift

International Earth Rotation and Reference Systems Service

Time and Frequency Standards Laboratory

Time deviation

Perman, Stacy (2013). A grand complication: the race to build the world's most legendary watch. New York: Atria. 978-1-439-19008-1.

ISBN

Berner, G.A., , Federation of the Swiss Watch Industry FH 1961 - 2012

Illustrated Professional Dictionary of Horology

Daniels, George, , London: Philip Wilson Publishers, 1981 (reprinted June 15, 2011)

Watchmaking

A Rudimentary Treatise on Clocks, Watches and Bells, 1903, from Project Gutenberg

Beckett, Edmund

Grafton, Edward, , London: Aylett and Jones, 1849

Horology, a popular sketch of clock and watch making

IEEE Guide for Measurement of Environmental Sensitivities of Standard Frequency Generators (Revision of IEEE Std 1193 - 1994), Piscataway, NJ: IEEE, :10.1109/ieeestd.2004.94440, ISBN 0-738-13711-1

doi

IEEE Standard Definitions of Physical Quantities for Fundamental Frequency and Time Metrology—Random Instabilities, Piscataway, NJ: IEEE, :10.1109/ieeestd.2008.4797525, ISBN 978-0-738-16855-5