measurement

meas·ure·ment

M0182500 (mĕzh′ər-mənt)n.1. The act of measuring or the process of being measured.2. A system of measuring: measurement in miles.3. The dimension, quantity, or capacity determined by measuring: the measurements of a room.

CONVERSION BETWEEN METRIC AND U.S. CUSTOMARY UNITS

FROM U.S. CUSTOMARY TO METRIC

When You Know	Multiply By	To Find
inches	25.4	millimeters
	2.54	centimeters
feet	30.48	centimeters
yards	0.91	meters
miles	1.61	kilometers
teaspoons	4.93	milliliters
tablespoons	14.79	milliliters
fluid ounces	29.57	milliliters
cups	0.24	liters
pints (liquid)	0.47	liters (liquid)
quarts (liquid)	0.95	liters (liquid)
gallons	3.79	liters
cubic feet	0.028	cubic meters
cubic yards	0.76	cubic meters
ounces	28.35	grams
pounds	0.45	kilograms
short tons (2,000 lbs)	0.91	metric tons
square inches	6.45	square centimeters
square feet	0.09	square meters
square yards	0.84	square meters
square miles	2.59	square kilometers
acres	0.40	hectares

FROM METRIC TO U.S. CUSTOMARY

When You Know	Multiply By	To Find
millimeters	0.04	inches
centimeters	0.39	inches
meters	3.28	feet
	1.09	yards
kilometers	0.62	miles
milliliters	0.20	teaspoons
	0.07	tablespoons
	0.03	fluid ounces
liters (liquid)	1.06	quarts (liquid)
	0.26	gallons
	4.23	cups
	2.12	pints (liquid)
cubic meters	35.31	cubic feet
	1.35	cubic yards
grams	0.035	ounces
kilograms	2.20	pounds
metric tons (1,000 kg)	1.10	short tons
square centimeters	0.155	square inches
square meters	1.20	square yards
square kilometers	0.39	square miles
hectares	2.47	acres

TEMPERATURE CONVERSION BETWEEN CELSIUS AND FAHRENHEIT

°C = (°F - 32) ÷ 1.8

°F = (°C × 1.8) + 32

UNITS OF THE INTERNATIONAL SYSTEM

The International System (abbreviated SI, for Système International, the French name for the system) was adopted in 1960 by the 11th General Conference on Weights and Measures. An expanded and modified version of the metric system, the International System addresses the needs of modern science for additional and more accurate units of measurement. The key features of the International System are decimalization, a system of prefixes, and a standard defined in terms of an invariable physical measure.

BASE UNITS

The International System has base units from which all others in the system are derived. The standards for the base units, except for the kilogram, are defined by unchanging and reproducible physical occurences. For example, the meter is defined as the distance traveled by light in a vacuum in 1/299,792,458 of a second. The standard for the kilogram is a platinum-iridium cylinder kept at the International Bureau of Weights and Standards in Sèvres, France.

Unit	Quantity	Symbol
meter	length	m
kilogram	mass	kg
second	time	s
ampere	electric current	A
kelvin	temperature	K
mole	amount of matter	mol
candela	luminous intensity	cd

PREFIXES

A multiple of a unit in the International System is formed by adding a prefix to the name of that unit. The prefixes change the magnitude of the unit by orders of ten from 1024 to 10-24.

Prefix	Symbol	Multiplying Factor
yotta-	Y	1024 = 1,000,000,000,000,000,000,000,000
zetta-	Z	1021 = 1,000,000,000,000,000,000,000
exa-	E	1018 = 1,000,000,000,000,000,000
peta-	P	1015 = 1,000,000,000,000,000
tera-	T	1012 = 1,000,000,000,000
giga-	G	109 = 1,000,000,000
mega-	M	106 = 1,000,000
kilo-	k	103 = 1,000
hecto-	h	102 = 100
deca-	da	10 = 10
deci-	d	10-1 = 0.1
centi-	c	10-2 = 0.01
milli-	m	10-3 = 0.001
micro-	μ	10-6 = 0.000,001
nano-	n	10-9 = 0.000,000,001
pico-	p	10-12 = 0.000,000,000,001
femto-	f	10-15 = 0.000,000,000,000,001
atto-	a	10-18 = 0.000,000,000,000,000,001
zepto-	z	10-21 = 0.000,000,000,000,000,000,001
yocto-	y	10-24 = 0.000,000,000,000,000,000,000,001

DERIVED UNITS

Most of the units in the International System are derived units, that is units defined in terms of base units and supplementary units. Derived units can be divided into two groups—those that have a special name and symbol, and those that do not.

WITHOUT NAMES AND SYMBOLS
Measure of	Derivation
acceleration	m/s2
angular acceleration	rad/s2
angular velocity	rad/s
density	kg/m3
electric field strength	V/m
luminance	cd/m2
magnetic field strength	A/m
velocity	m/s

WITH NAMES AND SYMBOLS
Unit	Measure of	Symbol	Derivation
coulomb	electric charge	C	A·s
farad	electric capacitance	F	A·s/V
henry	inductance	H	V·s/A
hertz	frequency	Hz	cycles/s
joule	quantity of energy	J	N·m
lumen	flux of light	lm	cd·sr
lux	illumination	lx	lm/m2
newton	force	N	kg·m/s2
ohm	electric resistance	Ω	V/A
pascal	pressure	Pa	N/m2
tesla	magnetic flux density	T	Wb/m2
volt	voltage	V	W/A
watt	power	W	J/s
weber	magnetic flux	Wb	V·s

measurement

(ˈmɛʒəmənt) n1. the act or process of measuring2. an amount, extent, or size determined by measuring3. a system of measures based on a particular standard

meas•ure•ment

(ˈmɛʒ ər mənt)

n. 1. the act of measuring. 2. a measured dimension. 3. extent, size, etc., ascertained by measuring. 4. a system of measuring or measures: liquid measurement.

meas·ure·ment

(mĕzh′ər-mənt) A method for determining quantity, capacity, or dimension. All systems of measurement use units whose amounts have been arbitrarily set and agreed upon by a group of people. Several systems of measurement are in common use, notably the United States Customary System and the metric system. The metric system has been officially adopted as the international standard for use in science, providing scientists all over the world with an efficient way of comparing the results of experiments conducted at different times and in different places.

Measurement

See also instruments.
acetimetrythe measurement of the relative amount of acetic acid in a given subtance. — acetimetrical, adj.acidimetryChemistry. the determination of the amount of free acid in a liquid. — acidimeter, n. — acidimetrical, adj.algometrymeasurement of pain by means of an algometer.atmidometrythe measurement of evaporation in the air. — atmidometer, n.autometry1. the measurement of oneself.
2. the measurement of a part of a figure as a fraction of the total figure’s height. — autometric, adj.baculometrythe measurement of distance or lines by means of a stave or staff.chorometrythe science of land surveying.chronoscopyaccurate measurement of short intervals of time by means of a chronoscope. — chronoscopic, adj.cosmometrythe science of measuring the universe.cryometrythe measurement of extremely low temperatures, by means of a cryometer.cyclometrythe measurement of circles.dosimetrythe measurement by a dosimeter of the dosage of radiation a per-son has received. See also drugs. — dosimetrist, n. — dosimetric, dosimetrical, adj.erythrocytometrymeasurement of the red blood cells in the blood, by use of an erythrocytometer.eudiometrythe science of measuring and analyzing gases by means of a eudiometer.fluorometrythe measurement of fluorescence, or visible radiation, by means of a fluorometer. — fluorometric, adj.galvanometrythe measurement of the strength of electric currents, by means of a galvanometer. — galvanometric, galvanometrical, adj.gasometrythe measurement of the amounts of the gases in a mixture. — gasometer, n. — gasometric, gasometrical, adj.goniometrythe practice or theory of measuring angles, especially by means of a goniometer.halometrythe measurement of the dimensions and angles of the planes of salt crystals. — halometer, n.heliometrythe practice of measuring the angular distance between stars by means of a heliometer. — heliometric, heliometrical, adj.horometrythe art or science of measuring time. — horometrical, adj.hypsometrythe measurement of altitude and heights, especially with refer-ence to sea level. — hypsometric, hypsometrical, adj.indigometrythe practice and art of determining the strength and coloring power of an indigo solution.isometryequality of measure. — isometric, isometrical, adj.konimetrythe measurement of impurities in the air by means of a konimeter. — konimetric, adj.kymography, cymography1. the measuring and recording of variations in fluid pressure, as blood pressure.
2. the measuring and recording of the angular oscillations of an aircraft in flight, with respect to an axis or axes flxed in space. — kymograph, n. — kymographic, adj.megameterRare. an instrument for measuring large objects. See also geography.mensuration1. the act, process, or science of measurement.
2. the branch of geometry dealing with measurement of length, area, or volume. — mensurate, mensurational, adj.metrologythe study and science of measures and weights. — metrologist, n. — metrological, adj.osmometrythe measurement of osmotic pressure, or the force a dissolved substance exerts on a semipermeable membrane through which it cannot pass when separated by it from a pure solvent. — osmometric, adj.osteometrythe measurement of bones.oxidimetrythe determination or estimation of the quantity of oxide formed on a substance. — oxidimetric, adj.pantometryObsolete, the realm of geometrical measurements, taken as a whole. — pantometer, n. — pantometric, pantometrical, adj.piezometrythe measurement of pressure or compressibility, as with a piezometer. — piezometric, adj.plastometrythe measurement of the plasticity of materials, as with a plastometer. — plastometric, adj.pulmometrythe measurement of the capacity of the lungs. — pulmometer, n.pyrometrythe measurement of temperatures greater than 1500 degrees Celsius. — pyrometer, n. — pyrometric, pyrometrical, adj.radiometrythe measurement of radiant energy by means of a radiometer. — radiometric, adj.rheometrythe measurement of electric current, usually with a galvanometer. — rheometric, adj.stadiaa means of surveying in which distances are measured by reading intervals on a graduated rod intercepted by two parallel cross hairs in the telescope of a surveying instrument. — stadia, adj.stereometry1. the process of determining the volume and dimensions of a solid.
2. the process of determining the specific gravity of a liquid. — stereometric, adj.tachymetrythe measurement of distance, height, elevation, etc., with a tachymeter.telemetrythe science or use of the telemeter; long-distance measurement.turbidimetrythe measurement of the turbidity of water or other fluids, as with a turbidimeter. — turbidimetric, adj.urinometrymeasurement of the specific gravity of urine, by means of an urinometer.volumenometrythe measurement of the volume of a solid body by means of a volumenometer.volumetrythe measurement of the volume of solids, gases, or liquids; volumetric analysis. — volumetric, volumetrical, adj.zoometrythe measurement and comparison of the sizes of animals and their parts. — zoometric, adj.

measurement

measure">measure1. 'measurement'

A measurement is a result obtained by measuring something.

Check the measurements carefully.Every measurement was exact.2. 'measure'

You do not use 'measurement' to refer to an action taken by a government. The word you use is measure.

Measures had been taken to limit the economic decline.Day nurseries were started as a war-time measure to allow mothers to work.

Thesaurus

Noun

measurement - the act or process of assigning numbers to phenomena according to a rule; "the measurements were carefully done"; "his mental measurings proved remarkably accurate"measuring, mensuration, measureactivity - any specific behavior; "they avoided all recreational activity"seismography - the measurement of tremors and shocks and undulatory movements of earthquakesquantitative analysis, quantitative chemical analysis - chemical analysis to determine the amounts of each element in the substanceactinometry - measuring the intensity of electromagnetic radiation (especially of the sun's rays)algometry - measuring sensitivity to pain or pressureanemography - recording anemometrical measurementsanemometry - measuring wind speed and directionangulation - the precise measurement of anglesanthropometry - measurement and study of the human body and its parts and capacitiesarterial blood gases - measurement of the pH level and the oxygen and carbon dioxide concentrations in arterial blood; important in diagnosis of many respiratory diseasesaudiometry - measuring sensitivity of hearingbathymetry, plumbing - measuring the depths of the oceanscalorimetry - measurement of quantities of heatcephalometry - measurement of human headsdensitometry - measuring the optical density of a substance by shining light on it and measuring its transmissiondosimetry - measuring the dose of radiation emitted by a radioactive sourcefetometry, foetometry - measurement of a fetus (especially the diameter of the head)gravimetry, hydrometry - the measurement of specific gravityhypsometry, hypsography - measurement of the elevation of land above sea levelmental measurement - a generic term used to cover any application of measurement techniques to the quantification of mental functionsmicrometry - measuring with a micrometerobservation - the act of making and recording a measurementpelvimetry - measurement of the dimensions of the bony birth canal (to determine whether vaginal birth is possible)photometry - measurement of the properties of light (especially luminous intensity)quantification - the act of discovering or expressing the quantity of somethingradioactive dating - measurement of the amount of radioactive material (usually carbon 14) that an object contains; can be used to estimate the age of the objectmeter reading, reading - the act of measuring with meters or similar instruments; "he has a job meter reading for the gas company"sampling - measurement at regular intervals of the amplitude of a varying waveform (in order to convert it to digital form)sounding - the act of measuring depth of water (usually with a sounding line)sound ranging - locating a source of sound (as an enemy gun) by measurements of the time the sound arrives at microphones in known positionsscaling - act of measuring or arranging or adjusting according to a scalespirometry - the use of a spirometer to measure vital capacitysurveying - the practice of measuring angles and distances on the ground so that they can be accurately plotted on a map; "he studied surveying at college"telemetry - automatic transmission and measurement of data from remote sources by wire or radio or other meansthermometry - the measurement of temperaturethermogravimetry - the measurement of changes in weight as a function of changes in temperature used as a technique of chemically analyzing substancestonometry - the measurement of intraocular pressure by determining the amount of force needed to make a slight indentation in the corneaviscometry, viscosimetry - the measurement of viscosity

measurement

noun1. size, length, dimension, area, amount, weight, volume, capacity, extent, height, depth, width, magnitude, amplitude Some of the measurements are doubtless inaccurate.2. calculation, assessment, evaluation, estimation, survey, judgment, valuation, appraisal, computation, calibration, mensuration, metage Measurement of blood pressure can be undertaken by the practice nurse.

measurement

nounThe act or process of ascertaining dimensions, quantity, or capacity:measure, mensuration, metrology.

Translations

尺寸测量量得的尺寸或大小等

measure

(ˈmeʒə) noun1. an instrument for finding the size, amount etc of something. a glass measure for liquids; a tape-measure.量具2. a unit. The metre is a measure of length.计量单位3. a system of measuring. dry/liquid/square measure.度量法4. a plan of action or something done. We must take (= use, or put into action) certain measures to stop the increase in crime.措施5. a certain amount. a measure of sympathy.适度6. (in music) the musical notes contained between two bar lines. （音乐）拍子，小节 verb1. to find the size, amount etc of (something). He measured the table.测量2. to show the size, amount etc of. A thermometer measures temperature.计量3. (with against, ~besides etc) to judge in comparison with. She measured her skill in cooking against her friend's.比较4. to be a certain size. This table measures two metres by one metre. 有...长（宽或高等） ˈmeasurement noun1. size, amount etc found by measuring. What are the measurements of this room?量得的尺寸或大小等2. the sizes of various parts of the body, usually the distance round the chest, waist and hips. What are your measurements, madam? （人体各部位的）尺寸 3. the act of measuring. We can find the size of something by means of measurement.测量beyond measure very great. I'm offering you riches beyond measure! 非常地，极其，无可估量 for good measure as something extra or above the minimum necessary. The shopkeeper weighed out the sweets and put in a few more for good measure.作为额外增添full measure (no less than) the correct amount. We must ensure that customers get full measure.份量足made to measure (of clothing) made to fit the measurements of a particular person: Was your jacket made to measure?; adjective (etc)a made-to-measure suit. 定制的measure out to mark (off), weigh (out) a certain distance, amount. He measured out a kilo of sugar. 标出，量出 measure up (often with to) to reach a certain required standard. John's performance doesn't measure up (to the others). 合格，符合标准

measurement

measurement,

determination of the magnitude of a quantity by comparison with a standard for that quantity. Quantities frequently measured include time, length, area, volume, pressure, mass, force, and energy. To express a measurement, there must be a basic unit of the quantity involved, e.g., the inch or second, and a standard of measurement (instrument) calibrated in such units, e.g., a ruler or clock. For convenience, such a standard is usually marked off both in multiples and in fractions of the basic unit. Although various systems of units exist for measuring different quantities (see weights and measuresweights and measures,
units and standards for expressing the amount of some quantity, such as length, capacity, or weight; the science of measurement standards and methods is known as metrology.

Crude systems of weights and measures probably date from prehistoric times.
..... Click the link for more information. ), the most important and widely used are the metric systemmetric system,
system of weights and measures planned in France and adopted there in 1799; it has since been adopted by most of the technologically developed countries of the world.
..... Click the link for more information. and the English units of measurementEnglish units of measurement,
principal system of weights and measures used in a few nations, the only major industrial one being the United States. It actually consists of two related systems—the U.S.
..... Click the link for more information. . Certain units have been defined for special applications, e.g., the light-yearlight-year,
in astronomy, unit of length equal to the distance light travels in one sidereal year. It is 9.461 × 10¹² km (about 6 million million mi). Alpha Centauri and Proxima Centauri, the stars nearest our solar system, are about 4.3 light-years distant.
..... Click the link for more information. and parsecparsec
[parallax + second], in astronomy, basic unit of length for measuring interstellar and intergalactic distances, equal to 206,265 times the distance from the earth to the sun, 3.26 light-years, or 3.08 × 10¹³ km (about 19 million million mi).
..... Click the link for more information. in astronomy and the angstromangstrom
, abbr. Å, unit of length equal to 10⁻¹⁰ meter (0.0000000001 meter); it is used to measure the wavelengths of visible light and of other forms of electromagnetic radiation, such as ultraviolet radiation and X rays.
..... Click the link for more information. in physics. Measurement is one of the fundamental processes of sciencescience
[Lat. scientia=knowledge]. For many the term science refers to the organized body of knowledge concerning the physical world, both animate and inanimate, but a proper definition would also have to include the attitudes and methods through which this body of
..... Click the link for more information. . It provides the data on which new theories are based and by which older theories are tested and retested. A good measurement should be both accurate and precise. Accuracy is determined by the care taken by the person making the measurement and the condition of the instrument; a worn or broken instrument or one carelessly used may give an inaccurate result. Precision, on the other hand, is determined by the design of the instrument; the finer the graduations on the instrument's scale and the greater the ease with which they can be read, the more precise the measurement. The choice of the instrument used should be appropriate to the desired precision of the results. The human foot may be a suitable instrument for pacing off short distances if precision is not important; at the other extreme, the interferometer (see interferenceinterference,
in physics, the effect produced by the combination or superposition of two systems of waves, in which these waves reinforce, neutralize, or in other ways interfere with each other.
..... Click the link for more information. ) is used for extremely precise measurements of distance in science. There is a basic distinction between measurement and counting. The result of counting is exact because it involves discrete entities that are not subdivided into fractions. Measurement, on the other hand, involves entities that may be subdivided into smaller and smaller fractions and is thus always an estimate. This distinction between measurement and counting seems, on the surface, to break down at the atomic level, where the quantum theoryquantum theory,
modern physical theory concerned with the emission and absorption of energy by matter and with the motion of material particles; the quantum theory and the theory of relativity together form the theoretical basis of modern physics.
..... Click the link for more information. reveals that not only mass (in the form of elementary particles and atoms) but also many other quantities occur only in discrete units, or quanta. It would seem, therefore, that one could, in theory, reduce measurement to counting at this level. However, the quantum theory also places limitations on the possibility of counting, stressing such concepts as the wavelike nature and indistinguishability of particles and proposing the uncertainty principleuncertainty principle,
physical principle, enunciated by Werner Heisenberg in 1927, that places an absolute, theoretical limit on the combined accuracy of certain pairs of simultaneous, related measurements.
..... Click the link for more information. as an absolute limitation on certain pairs of related measurements.

measurement

see CRITERIA AND LEVELS OF MEASUREMENT.

Measurement

an operation by means of which the ratio of one quantity (the quantity being measured) to another quantity of the same kind (taken as a unit) is determined; the number that expresses this ratio is called the numerical value of the quantity being measured.

Measurement is one of the oldest operations; it was used by man in practical activities (for distributing plots of land, in construction, and in irrigation work). Modern economic and social activities would be inconceivable without measurement.

An organic relation between observation and experiment, including the determination of the numerical values of the characteristics of objects and processes under study, is characteristic of the exact sciences. D.I. Mendeleev repeatedly emphasized that science begins with measurement.

A completed measurement includes the following elements: the object of measurement, a property or state of which is characterized by the measured quantity; a unit of measurement; technical measurement devices, graduated in the selected units; a method of measurement; an observer or recording device to register the result of the measurement; and the final result of the measurement.

Direct measurement, in which the result is obtained directly from measurement of the quantity itself (for example, measurement of the length of a graduated ruler or of the mass of a body by means of weights), is the simplest and historically the first known type of measurement. However, direct measurements are not always possible. In such cases, indirect measurements based on a known relation between the unknown quantity and the quantities being measured directly are used.

The causes and quantitative relationships that have been established by science between physical phenomena that differ in nature made it possible to devise a self-consistent system of units (the International System of Units) that is used in all fields of measurement.

Measurement should be distinguished from other means of quantitative characterization of quantities that are used when there is no unambiguous correspondence between a quantity and its quantitative expression in specified units. Thus, the visual determination of wind speed according to the Beaufort scale or of the hardness of minerals according to Mohs’ scale should be regarded as estimation rather than measurement.

Any measurement inevitably entails errors. Measurement errors caused by imperfection of the measuring method, by inaccurate gradation, and by incorrect installation of measuring equipment are called systematic errors. Systematic errors are eliminated by introducing experimentally determined corrections. Errors of another type—random errors—are due to the influence of uncontrollable factors, such as vibrations or random fluctuations of temperature, on the result of the measurement. Random errors are estimated by methods of mathematical statistics on the basis of data from repeated measurements.

In some cases—which are encountered particularly frequently in atomic and nuclear physics—the variability of the results of measurement is associated not only with equipment errors but also with the nature of the very phenomena being studied. For example, if a bundle of identically accelerated electrons is passed through the slit of a diffraction grating, electrons will strike various points of a screen mounted beyond the grating with a certain probability. This example shows that the extension of measurement to new fields of physics requires review and revision of the concepts used in measurements in other fields. Another important problem, the automation of measurement, arose with the development of science and technology. It is connected, on the one hand, with the conditions under which modern measurements are made (such as nuclear reactors and outer space) and, on the other, with the imperfection of the human sense organs. In modern industry, particularly at high speeds, pressures, and temperatures, the direct coupling of measuring devices to controls, bypassing humans, makes possible conversion to the most advanced form of production—automated production.

In metrology, aggregate and joint measurements are considered in addition to direct and indirect measurements. Measurements of several similar quantities whose values are found by solving a system of equations obtained as a result of direct measurements of various combinations of these quantities (such as the calibration of a set of weights when the values of the mass of the weights are found on the basis of direct measurement of the mass of one and comparison of the masses of various combinations of the weights) are called aggregate measurements. Joint measurements are simultaneous measurements of two or more various quantities for the purpose of finding a relation between or among them (for example, finding the dependence of the elongation of a body on temperature).

A distinction is also made between absolute and relative measurements. Absolute measurements include indirect measurements, which are based on the measurement of one or more basic quantities (such as length, mass, or time) and on the use of the values of fundamental physical constants in terms of which the physical quantity being measured can be expressed. Relative measurements are understood to be measurements either of the ratio of a quantity to a like quantity that plays the role of an arbitrary unit or of a change in a quantity with respect to another quantity that is used as a base.

The value of a quantity that is found as a result of measurement is the product of an abstract number (the numerical value) and a unit of the given quantity.

Because of errors, the results of a measurement always differ somewhat from the true value of the quantity being measured; therefore, the results of measurement are usually accompanied by an indication of the estimated error.

The uniformity of measurements in a country is provided by the metrological service, which keeps standard units and checks the measuring devices used. The classification of measurements according to the objects being measured has come into wide use. According to this classification, distinction is made among linear measurements (measurements of length, area, and volume), mechanical measurements (measurements of force, pressure, and other quantities), and electrical measurements. In general this classification corresponds to the main branches of the discipline of physics.

REFERENCES

Malikov, S. F., and N.I. Tiurin. Vvedenie v metrologiiu, 2nd ed. Moscow, 1966.
Malikov, S.F. Vvedenie v tekhniku izmerenii, 2nd ed. Moscow, 1952.
Jánossy, L. Teoriia i praktika obrabotki rezul’tatov izmerenii, 2nd ed. Moscow, 1968. (Translated from English.)
Izmeritel’naia tekhnika, 1961, no. 12; 1962, nos. 4, 6, 8, 9, and 10. [section updated]
In mathematical theory, measurement moves away from the limited accuracy of physical measurements. The problem of measuring a quantity Q by means of a unit of measurement U consists in finding the numerical factor q in the equation
Q = qU
In this case Q and U are considered to be positive scalar quantities of the same kind, and the factor q is a positive real number that may be either rational or irrational. For a rational number q = m/n (m and n are natural numbers), equation (1) has an extremely simple meaning: it indicates that there exists a quantity V (an nth of U) which, when taken as a term n times, gives U or, when taken as a term m times, gives Q:
U = nV Q = mV
In this case the quantities Q and U are said to be commensurable. For incommensurable U and Q the factor q is irrational (for example, it may be equal to π if Q is the circumference and U the diameter of a circle). In this case the determination of the meaning of equation (1) is somewhat more complex. It may be determined in the following manner: equation (1) means that for any rational number r,
Q > rU follows from q > r
and Q < rU follows from q < r
It is sufficient to require that condition (2) be satisfied for all decimal approximations of q that are less than or greater than q. It should be noted that historically the very concept of irrational number arose from the problem of measurement, so that the original problem in the case of incommensurate quantities consisted not in determining the meaning of equation (1) on the basis of the ready theory of real numbers but in determining the meaning of the symbol q, which reflects the result of a comparison of quantity Q and the unit of measurement U. For example, according to the definition of the German mathematician R. Dedekind, an irrational number is a “cross section” in the system of rational numbers. Such a cross section appears naturally when the two incommensurate quantities Q and U are compared. With respect to these quantities, all rational numbers are divided into two classes: the class R₁ of the rational numbers r, for which Q > rU, and the class R₂ of the rational numbers r, for which Q < rU.
The approximate measurement of quantities by means of rational numbers is of great importance. The error of an approximate equation Q ≃ rU is equal to Δ = (r – q)U. It is natural to seek r = m/n for which the error is less than for any number r′ = m′/n′ with the denominator n′ ≤ n. Approximations of this type are supplied by the suitable fractions r₁, r₂, r₃, … of the number q, which are found by using the theory of continued fractions. For example, for a circumference S measured in the diameter U, the approximations are

and so on; for the length of the year Q measured in days U, the approximations are

A. N. KOLMOGOROV

Measurement in social research (such as statistics, sociology, psychology, economics, and ethnology) is a method of ordering social data in which the systems of numbers and relationships among them are placed in correspondence with a number of social factors being measured. The different measures of the recurrence and reproducibility of social facts are the social measurements, or scales. Simple scales—such as monetary evaluation of labor, skill ratings, and the assessment of success in schooling (the grading system) and sports—come into use with the development of society. Measurement in the social sciences differs from such “natural” scales in the precise determination of measured attributes and rules for constructing the scale.

Measurements first came into use in social studies in the 1920’s and 1930’s, when investigators encountered the problem of reliability in the study of social consciousness, sociopsychological aims (relations), social and occupational status, public opinion, and qualitative characterization of working and everyday conditions. These measurements are an example of standardized group assessment, in which the “intensity” of public opinion is measured by sampling statistics.

Measurements are divided into three types: (1) nominal measurements, which are numbers assigned to objects on a nominal scale that merely state the difference or identity of the objects (that is, a nominal scale is essentially a grouping or classification); (2) ordinal measurements, in which the numbers assigned to objects on the scale order them according to the measured attribute but indicate only the procedure of placing the objects on the scale and not the distance between objects, much less the coordinates; (3) interval measurements, in which the numbers assigned to objects on the scale indicate not only the order of the objects but also the distance between them. For example, the scale of attractiveness of vocations is an interval measurement. Such a scale, by assigning a standard rating to each vocation, makes it possible to compare vocations in terms of popularity, that is, to assert that, for example, the job of driver is M points more popular than that of mechanic and K points less popular than that of pilot. However, it does not make possible the assertion that the interest in the jobs of driver and mechanic exceeds the interest in the job of pilot if the sum of corresponding points exceeds the rating of the vocation of pilot. The determination of a quantitative measure of social phenomena and processes is limited to these three types of measurement. Attempts are being made to create a fourth type of measurement—quantitative measurement—by introducing a unit of measurement.

REFERENCES

Iadov, V.A. Metodologiia i protsedury sotsiologicheskikh issledovanii. Tartu, 1968.
Zdravomyslov, A.G. Metodologiia i protsedura sotsiologicheskikh is sledovanii. Moscow, 1969.

IU. B. SAMSONOV

What does it mean when you dream about measurement?

If we dream about something being measured out, it may represent a feeling of waiting, of “How long will this last?” It could also allude to the fact that we are making comparisons in our waking life.

measurement

[′mezh·ər·mənt] (science and technology) The process of determining the value of some quantity in terms of a standard unit.

measurement

(testing)The act or process of measuring; a figure, extent,or amount obtained by measuring.

measurement

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CONVERSION BETWEEN METRIC AND U.S. CUSTOMARY UNITS

FROM U.S. CUSTOMARY TO METRIC

FROM METRIC TO U.S. CUSTOMARY

TEMPERATURE CONVERSION BETWEEN CELSIUS AND FAHRENHEIT

UNITS OF THE INTERNATIONAL SYSTEM

BASE UNITS

PREFIXES

DERIVED UNITS

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Measurement

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What does it mean when you dream about measurement?

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Patient discussion about measurement

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Synonyms for measurement

noun size

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noun calculation

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Synonyms for measurement

noun the act or process of ascertaining dimensions, quantity, or capacity

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Synonyms for measurement

noun the act or process of assigning numbers to phenomena according to a rule

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