154 relations: Absolute zero, Accuracy and precision, Airy points, Ampere, Approximation, Avogadro constant, Axel Springer SE, Behavioural sciences, Boltzmann constant, Candela, Carbon, Caribbean, Centimetre, Centimetre–gram–second system of units, Charles Sanders Peirce, Commerce, Commonwealth of Nations, Conversion of units, Correction for attenuation, Council for Scientific and Industrial Research, Day, Detection limit, Differential nonlinearity, Dimensional analysis, Dimensionless quantity, Drag (physics), Econometrics, Edmund Gunter, Electric current, Electrical measurements, Engineering, English units, Euclid's Elements, Fathom, Fraction (mathematics), Free fall, French language, General Conference on Weights and Measures, Geometry, Gram, Gravity, Gunter's chain, History of measurement, History of science and technology, History of timekeeping devices, Hour, Imperial units, Inch, Information theory, Instrumentation, ..., Integral linearity, International Bureau of Weights and Measures, International System of Units, Isaac Newton, ISO 10012, Isotopes of caesium, John Wallis, Kelvin, Key relevance, Kilogram, Kilometre, Least count, Length, Level of measurement, List of humorous units of measurement, List of unusual units of measurement, Luminous intensity, Magnitude (mathematics), Mass, Mean, Measurement in quantum mechanics, Measurement problem, Measurement uncertainty, Measuring instrument, Metre, Metre Convention, Metric prefix, Metric system, Metrology, Michelson–Morley experiment, Mile, Millimetre, Mole (unit), Month, National Institute of Standards and Technology, National Measurement Institute, Australia, National Physical Laboratory (United Kingdom), National Physical Laboratory of India, Natural science, NCSL International, Number sense, Observable variable, Observation, Observational error, Operation (mathematics), Order of magnitude, Ounce, Physical constant, Plan, Planck constant, Positivism, Pound (mass), Power of 10, Primary instrument, Psychometrics, Quantification (science), Quantitative research, Quantum, Quantum mechanics, Questionnaire, Range (mathematics), Real versus nominal value (economics), Remote sensing, Rod (unit), Ruler, Sèvres, Science, Second, SI base unit, Social science, Spectral line, Spectrum, Square root, Standard (metrology), Stanley Smith Stevens, Statistics, Stone (unit), System of measurement, Technical drawing, Technology, Temperature, Test method, Theory of conjoint measurement, Time, Timeline of temperature and pressure measurement technology, Timeline of time measurement technology, Ton, Trade, Triple point, Uncertainty, Uncertainty principle, Unit of measurement, United States customary units, United States Department of Commerce, Vacuum permeability, Vacuum permittivity, Virtual instrumentation, Watt, Wave function, Wave function collapse, Wavelength, Web analytics, Week, Year. Expand index (104 more) » « Shrink index
Absolute zero is the lower limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reach their minimum value, taken as 0.
Precision is a description of random errors, a measure of statistical variability.
Airy points (after George Biddell Airy) are used for precision measurement (metrology) to support a length standard in such a way as to minimise bending or droop of a horizontally supported beam.
The ampere (symbol: A), often shortened to "amp",SI supports only the use of symbols and deprecates the use of abbreviations for units.
An approximation is anything that is similar but not exactly equal to something else.
In chemistry and physics, the Avogadro constant (named after scientist Amedeo Avogadro) is the number of constituent particles, usually atoms or molecules, that are contained in the amount of substance given by one mole.
Axel Springer SE is the largest digital publishing house in Europe, with numerous multimedia news brands, such as Bild, Die Welt, and Fakt and more than 15,000 employees.
The term behavioral sciences encompasses the various disciplines that explores the cognitive processes within organisms and the behavioural interactions between organisms in the natural world.
The Boltzmann constant, which is named after Ludwig Boltzmann, is a physical constant relating the average kinetic energy of particles in a gas with the temperature of the gas.
The candela (or; symbol: cd) is the base unit of luminous intensity in the International System of Units (SI); that is, luminous power per unit solid angle emitted by a point light source in a particular direction.
Carbon (from carbo "coal") is a chemical element with symbol C and atomic number 6.
The Caribbean is a region that consists of the Caribbean Sea, its islands (some surrounded by the Caribbean Sea and some bordering both the Caribbean Sea and the North Atlantic Ocean) and the surrounding coasts.
A centimetre (international spelling as used by the International Bureau of Weights and Measures; symbol cm) or centimeter (American spelling) is a unit of length in the metric system, equal to one hundredth of a metre, centi being the SI prefix for a factor of.
The centimetre–gram–second system of units (abbreviated CGS or cgs) is a variant of the metric system based on the centimetre as the unit of length, the gram as the unit of mass, and the second as the unit of time.
Charles Sanders Peirce ("purse"; 10 September 1839 – 19 April 1914) was an American philosopher, logician, mathematician, and scientist who is sometimes known as "the father of pragmatism".
Commerce relates to "the exchange of goods and services, especially on a large scale.” Commerce includes legal, economic, political, social, cultural and technological systems that operate in any country or internationally.
The Commonwealth of Nations, often known as simply the Commonwealth, is an intergovernmental organisation of 53 member states that are mostly former territories of the British Empire.
Conversion of units is the conversion between different units of measurement for the same quantity, typically through multiplicative conversion factors.
Correction for attenuation is a statistical procedure, due to Spearman (1904), to "rid a correlation coefficient from the weakening effect of measurement error" (Jensen, 1998), a phenomenon known as regression dilution.
The Council for Scientific and Industrial Research (CSIR) is South Africa's central and premier scientific research and development organisation.
A day, a unit of time, is approximately the period of time during which the Earth completes one rotation with respect to the Sun (solar day).
In analytical chemistry, the detection limit, lower limit of detection, or LOD (limit of detection), is the lowest quantity of a substance that can be distinguished from the absence of that substance (a blank value) with a stated confidence level (generally 99%).
Differential nonlinearity (acronym DNL) is a term describing the deviation between two analog values corresponding to adjacent input digital values.
In engineering and science, dimensional analysis is the analysis of the relationships between different physical quantities by identifying their base quantities (such as length, mass, time, and electric charge) and units of measure (such as miles vs. kilometers, or pounds vs. kilograms) and tracking these dimensions as calculations or comparisons are performed.
In dimensional analysis, a dimensionless quantity is a quantity to which no physical dimension is assigned.
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid.
Econometrics is the application of statistical methods to economic data and is described as the branch of economics that aims to give empirical content to economic relations.
Edmund Gunter (1581 – 10 December 1626), was an English clergyman, mathematician, geometer and astronomer of Welsh descent.
An electric current is a flow of electric charge.
Electrical measurements are the methods, devices and calculations used to measure electrical quantities.
Engineering is the creative application of science, mathematical methods, and empirical evidence to the innovation, design, construction, operation and maintenance of structures, machines, materials, devices, systems, processes, and organizations.
English units are the historical units of measurement used in England up to 1826 (when they were replaced by Imperial units), which evolved as a combination of the Anglo-Saxon and Roman systems of units.
The Elements (Στοιχεῖα Stoicheia) is a mathematical treatise consisting of 13 books attributed to the ancient Greek mathematician Euclid in Alexandria, Ptolemaic Egypt c. 300 BC.
A fathom is a unit of length in the imperial and the U.S. customary systems equal to, used especially for measuring the depth of water.
A fraction (from Latin fractus, "broken") represents a part of a whole or, more generally, any number of equal parts.
In Newtonian physics, free fall is any motion of a body where gravity is the only force acting upon it.
French (le français or la langue française) is a Romance language of the Indo-European family.
The General Conference on Weights and Measures (Conférence générale des poids et mesures – CGPM) is the supreme authority of the International Bureau of Weights and Measures (Bureau international des poids et mesures – BIPM), the inter-governmental organization established in 1875 under the terms of the Metre Convention (Convention du Mètre) through which Member States act together on matters related to measurement science and measurement standards.
Geometry (from the γεωμετρία; geo- "earth", -metron "measurement") is a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space.
The gram (alternative spelling: gramme; SI unit symbol: g) (Latin gramma, from Greek γράμμα, grámma) is a metric system unit of mass.
Gravity, or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light—are brought toward (or gravitate toward) one another.
Gunter's chain or the surveyor's chain (also known as Gunter’s measurement or surveyor’s measurement) is a distance measuring device used for land survey.
The earliest recorded systems of weights and measures originate in the 3rd or 4th millennium BC.
The history of science and technology (HST) is a field of history which examines how humanity's understanding of the natural world (science) and ability to manipulate it (technology) have changed over the centuries.
For thousands of years, devices have been used to measure and keep track of time.
An hour (symbol: h; also abbreviated hr.) is a unit of time conventionally reckoned as of a day and scientifically reckoned as 3,599–3,601 seconds, depending on conditions.
The system of imperial units or the imperial system (also known as British Imperial or Exchequer Standards of 1825) is the system of units first defined in the British Weights and Measures Act of 1824, which was later refined and reduced.
The inch (abbreviation: in or &Prime) is a unit of length in the (British) imperial and United States customary systems of measurement now formally equal to yard but usually understood as of a foot.
Information theory studies the quantification, storage, and communication of information.
Instrumentation is a collective term for measuring instruments used for indicating, measuring and recording physical quantities, and has its origins in the art and science of scientific instrument-making.
A measurement system consists of a sensor, to input the physical parameter that is of interest, and an output to a medium that is suitable for reading by the system that needs to know the value of the parameter.
The International Bureau of Weights and Measures (Bureau international des poids et mesures) is an intergovernmental organization established by the Metre Convention, through which Member States act together on matters related to measurement science and measurement standards.
The International System of Units (SI, abbreviated from the French Système international (d'unités)) is the modern form of the metric system, and is the most widely used system of measurement.
Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, astronomer, theologian, author and physicist (described in his own day as a "natural philosopher") who is widely recognised as one of the most influential scientists of all time, and a key figure in the scientific revolution.
ISO 10012:2003, Measurement management systems - Requirements for measurement processes and measuring equipment is the ISO standard that specifies generic requirements and provides guidance for the management of measurement processes and metrological confirmation of measuring equipment used to support and demonstrate compliance with metrological requirements.
Caesium (55Cs; or cesium) has 40 known isotopes, making it, along with barium and mercury, the element with the most isotopes.
John Wallis (3 December 1616 – 8 November 1703) was an English clergyman and mathematician who is given partial credit for the development of infinitesimal calculus.
The Kelvin scale is an absolute thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics.
In master locksmithing, key relevance is the measurable difference between an original key and a copy made of that key, either from a wax impression or directly from the original, and how similar the two keys are in size and shape.
The kilogram or kilogramme (symbol: kg) is the base unit of mass in the International System of Units (SI), and is defined as being equal to the mass of the International Prototype of the Kilogram (IPK, also known as "Le Grand K" or "Big K"), a cylinder of platinum-iridium alloy stored by the International Bureau of Weights and Measures at Saint-Cloud, France.
The kilometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: km; or) or kilometer (American spelling) is a unit of length in the metric system, equal to one thousand metres (kilo- being the SI prefix for). It is now the measurement unit used officially for expressing distances between geographical places on land in most of the world; notable exceptions are the United States and the road network of the United Kingdom where the statute mile is the official unit used.
In metrology, the least count of a measuring instrument is the smallest change in the measured quantity that can be resolved on the instrument's scale.
In geometric measurements, length is the most extended dimension of an object.
Level of measurement or scale of measure is a classification that describes the nature of information within the values assigned to variables.
Many people have made use of, or invented, units of measurement intended primarily for their humour value.
An unusual unit of measurement is a unit of measurement that does not form part of a coherent system of measurement; especially in that its exact quantity may not be well known or that it may be an inconvenient multiple or fraction of base units in such systems.
In photometry, luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye.
In mathematics, magnitude is the size of a mathematical object, a property which determines whether the object is larger or smaller than other objects of the same kind.
Mass is both a property of a physical body and a measure of its resistance to acceleration (a change in its state of motion) when a net force is applied.
In mathematics, mean has several different definitions depending on the context.
The framework of quantum mechanics requires a careful definition of measurement.
The measurement problem in quantum mechanics is the problem of how (or whether) wave function collapse occurs.
In metrology, measurement uncertainty is a non-negative parameter characterizing the dispersion of the values attributed to a measured quantity.
A measuring instrument is a device for measuring a physical quantity.
The metre (British spelling and BIPM spelling) or meter (American spelling) (from the French unit mètre, from the Greek noun μέτρον, "measure") is the base unit of length in some metric systems, including the International System of Units (SI).
The Metre Convention (Convention du Mètre), also known as the Treaty of the Metre, is an international treaty that was signed in Paris on 20 May 1875 by representatives of 17 nations (Argentina, Austria-Hungary, Belgium, Brazil, Denmark, France, Germany, Italy, Peru, Portugal, Russia, Spain, Sweden and Norway, Switzerland, Turkey, United States of America, and Venezuela).
A metric prefix is a unit prefix that precedes a basic unit of measure to indicate a multiple or fraction of the unit.
The metric system is an internationally adopted decimal system of measurement.
Metrology is the science of measurement.
The Michelson–Morley experiment was performed between April and July, 1887 by Albert A. Michelson and Edward W. Morley at what is now Case Western Reserve University in Cleveland, Ohio, and published in November of the same year.
The mile is an English unit of length of linear measure equal to 5,280 feet, or 1,760 yards, and standardised as exactly 1,609.344 metres by international agreement in 1959.
The millimetre (International spelling as used by the International Bureau of Weights and Measures; SI unit symbol mm) or millimeter (American spelling) is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length.
The mole, symbol mol, is the SI unit of amount of substance.
A month is a unit of time, used with calendars, which is approximately as long as a natural period related to the motion of the Moon; month and Moon are cognates.
The National Institute of Standards and Technology (NIST) is one of the oldest physical science laboratories in the United States.
The National Measurement Institute (NMI) is Australia's peak measurement body responsible for biological, chemical, legal and physical measurement and is currently administered within the Australian Government's Department of Industry.
The National Physical Laboratory (NPL) is the national measurement standards laboratory for the United Kingdom, based at Bushy Park in Teddington, London, England.
The National Physical Laboratory of India, situated in New Delhi, is the measurement standards laboratory of India.
Natural science is a branch of science concerned with the description, prediction, and understanding of natural phenomena, based on empirical evidence from observation and experimentation.
NCSL International (NCSLI) (from the founding name "National Conference of Standards Laboratories") is a global, non-profit organization whose membership is open to any organization with an interest in metrology (the science of measurement) and its application in research, development, education, and commerce.
In mathematics education, number sense can refer to "an intuitive understanding of numbers, their magnitude, relationships, and how they are affected by operations".
In statistics, observable variable or observable quantity (also manifest variables), as opposed to latent variable, is a variable that can be observed and directly measured.
Observation is the active acquisition of information from a primary source.
Observational error (or measurement error) is the difference between a measured value of a quantity and its true value.
In mathematics, an operation is a calculation from zero or more input values (called operands) to an output value.
An order of magnitude is an approximate measure of the number of digits that a number has in the commonly-used base-ten number system.
The ounce (abbreviated oz; apothecary symbol: ℥) is a unit of mass, weight, or volume used in most British derived customary systems of measurement.
A physical constant, sometimes fundamental physical constant or universal constant, is a physical quantity that is generally believed to be both universal in nature and have constant value in time.
A plan is typically any diagram or list of steps with details of timing and resources, used to achieve an objective to do something.
The Planck constant (denoted, also called Planck's constant) is a physical constant that is the quantum of action, central in quantum mechanics.
Positivism is a philosophical theory stating that certain ("positive") knowledge is based on natural phenomena and their properties and relations.
The pound or pound-mass is a unit of mass used in the imperial, United States customary and other systems of measurement.
In mathematics, a power of 10 is any of the integer powers of the number ten; in other words, ten multiplied by itself a certain number of times (when the power is a positive integer).
A primary instrument is a scientific instrument, which by its physical characteristics is accurate and is not calibrated against anything else.
Psychometrics is a field of study concerned with the theory and technique of psychological measurement.
In mathematics and empirical science, quantification (or quantitation) is the act of counting and measuring that maps human sense observations and experiences into quantities.
In natural sciences and social sciences, quantitative research is the systematic empirical investigation of observable phenomena via statistical, mathematical or computational techniques.
In physics, a quantum (plural: quanta) is the minimum amount of any physical entity (physical property) involved in an interaction.
Quantum mechanics (QM; also known as quantum physics, quantum theory, the wave mechanical model, or matrix mechanics), including quantum field theory, is a fundamental theory in physics which describes nature at the smallest scales of energy levels of atoms and subatomic particles.
A questionnaire is a research instrument consisting of a series of questions (or other types of prompts) for the purpose of gathering information from respondents.
In mathematics, and more specifically in naive set theory, the range of a function refers to either the codomain or the image of the function, depending upon usage.
In economics, a real value of a good or other entity has been adjusted for inflation, enabling comparison of quantities as if prices had not changed.
Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object and thus in contrast to on-site observation.
The rod or perch or pole is a surveyor’s tool and unit of length equal to yards, 16 feet, of a statute mile or one-fourth of a surveyor's chain and 5.0292 meters.
A ruler, sometimes called a rule or line gauge, is a device with equally spaced markings along its length, used in geometry, technical drawing, engineering and building to measure distances or to rule straight lines.
Sèvres is a commune in the southwestern suburbs of Paris, France.
R. P. Feynman, The Feynman Lectures on Physics, Vol.1, Chaps.1,2,&3.
The second is the SI base unit of time, commonly understood and historically defined as 1/86,400 of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each.
The International System of Units (SI) defines seven units of measure as a basic set from which all other SI units can be derived.
Social science is a major category of academic disciplines, concerned with society and the relationships among individuals within a society.
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies.
A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary, without steps, across a continuum.
In mathematics, a square root of a number a is a number y such that; in other words, a number y whose square (the result of multiplying the number by itself, or) is a. For example, 4 and −4 are square roots of 16 because.
In metrology (the science of measurement), a standard (or etalon) is an object, system, or experiment that bears a defined relationship to a unit of measurement of a physical quantity.
Stanley Smith Stevens (November 4, 1906 – January 18, 1973) was an American psychologist who founded Harvard's Psycho-Acoustic Laboratory, studying psychoacoustics, and he is credited with the introduction of Stevens's power law.
Statistics is a branch of mathematics dealing with the collection, analysis, interpretation, presentation, and organization of data.
The stone or stone weight (abbreviation: st.) is an English and imperial unit of mass now equal to 14 pounds (6.35029318 kg).
A system of measurement is a collection of units of measurement and rules relating them to each other.
Technical drawing, drafting or drawing, is the act and discipline of composing drawings that visually communicate how something functions or is constructed.
Technology ("science of craft", from Greek τέχνη, techne, "art, skill, cunning of hand"; and -λογία, -logia) is first robustly defined by Jacob Bigelow in 1829 as: "...principles, processes, and nomenclatures of the more conspicuous arts, particularly those which involve applications of science, and which may be considered useful, by promoting the benefit of society, together with the emolument of those who pursue them".
Temperature is a physical quantity expressing hot and cold.
A test method is a method for a test in science or engineering, such as a physical test, chemical test, or statistical test.
The theory of conjoint measurement (also known as conjoint measurement or additive conjoint measurement) is a general, formal theory of continuous quantity.
Time is the indefinite continued progress of existence and events that occur in apparently irreversible succession from the past through the present to the future.
Timeline of temperature and pressure measurement technology.
Timeline of time measurement technology.
The ton is a unit of measure.
Trade involves the transfer of goods or services from one person or entity to another, often in exchange for money.
In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium.
Uncertainty has been called "an unintelligible expression without a straightforward description".
In quantum mechanics, the uncertainty principle (also known as Heisenberg's uncertainty principle) is any of a variety of mathematical inequalities asserting a fundamental limit to the precision with which certain pairs of physical properties of a particle, known as complementary variables, such as position x and momentum p, can be known.
A unit of measurement is a definite magnitude of a quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same kind of quantity.
United States customary units are a system of measurements commonly used in the United States.
The United States Department of Commerce is the Cabinet department of the United States government concerned with promoting economic growth.
The physical constant μ0, (pronounced "mu naught" or "mu zero"), commonly called the vacuum permeability, permeability of free space, permeability of vacuum, or magnetic constant, is an ideal, (baseline) physical constant, which is the value of magnetic permeability in a classical vacuum.
The physical constant (pronounced as "epsilon nought"), commonly called the vacuum permittivity, permittivity of free space or electric constant, is an ideal, (baseline) physical constant, which is the value of the absolute dielectric permittivity of classical vacuum.
Virtual instrumentation is the use of customizable software and modular measurement hardware to create user-defined measurement systems, called virtual instruments.
The watt (symbol: W) is a unit of power.
A wave function in quantum physics is a mathematical description of the quantum state of an isolated quantum system.
In quantum mechanics, wave function collapse is said to occur when a wave function—initially in a superposition of several eigenstates—appears to reduce to a single eigenstate (by "observation").
In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
Web analytics is the measurement, collection, analysis and reporting of web data for purposes of understanding and optimizing web usage.
A week is a time unit equal to seven days.
A year is the orbital period of the Earth moving in its orbit around the Sun.