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Measurement term English and analysis

measurement of its value during measurement can be considered as a constant quantity

note: the word static is applicable to the measured, not to the measurement method

dynamic measurement

measurement of the instantaneous value of [variable] or the change value with time

note: the word "dynamic" is applicable to the measured, not to the measurement method

principle of measurement

scientific basis of measurement method. For example, Josephson effect applied to voltage measurement

measurement method of measurement

according to the given principle, the theoretical operation and practical operation method involved in the implementation of measurement

measurement procedure

according to the given method, the theoretical calculation and practical operation steps involved in the implementation of measurement

measured, measured quantity, quantity to be measured

measured quantity

measured variable

measured variable

input variable

the variable input to the instrument

output variable

the variable output by the instrument

measured valud

at the moment of specified conditions, it is equivalent to the information obtained by the measuring device and expressed in numerical values and measurement units

[measured] transformed [of a measure]

represents the quantity value that has a functional relationship with the measured value. For example, the electrical output signal value of the pressure sensor

note: the transformation value can be the value inside the measurement system or the output provided from the system

influence quantity

the quantity that does not belong to the measured value but affects the measured value or the indicated value of the measuring instrument. For example: ambient temperature, frequency of measured AC voltage

signal

a physical variable that contains information about one or more variables represented by one or more parameters

note: these parameters are called signal information parameters. For example, for amplitude modulated sinusoidal carriers, the instantaneous amplitude is the information parameter of the signal; For pulse signals modulated by duration or position, the duration or position of each pulse is the information parameter of the signal respectively

measurement signal

a signal in the measurement system that represents the measured signal

analog signal

information parameters are continuous signals of all values within a given range

digital signal

information parameters are represented by signals of each value in a set of discrete values expressed in numbers

standardized signal

signal with standardized upper and lower range values

input signal30nl

the signal applied to the input end of the instrument

output signal

the signal sent by the output end of the instrument

quantized signal

signal with quantized information parameters

binary signal

a binary quantized signal usually represented by 0 to 1

direct method of measurement

the measurement method of the measured value can be obtained directly without measuring other quantities that have a functional relationship with the measured value. For example: measure the length with a scale; Measure the mass with an equal arm balance

note: in order to make corresponding correction, supplementary measurement is needed to determine the value of the influence quantity. This measurement method is still the direct measurement method

indirect method of measurement

the measurement method of the measured value can be obtained by measuring other quantities that have a functional relationship with the measured value. For example, measure the pressure by measuring the height of the liquid column

basic method of measurement

a measurement method that determines the measured value by measuring some basic quantities

Direct comparison method of measurementa measurement method that directly compares the measured quantity with the same quantity whose value is known. For example, measure the length with a scale

substitution method of measurement

substitute the selected quantity with known value for the measured one, so that the same effect can be obtained on the indicating device to determine the measured measurement method. For example, use the balance and some weights with known mass to determine the mass by the Borda substitution method

differential method of measurement

compare the measured value with the same kind of known quantity that is only slightly different from its quantity value, and measure the difference between the two quantities to determine the measurement method of the measured value. For example, the measuring block and comparator measure the diameter of the piston to enhance the investment confidence of various enterprises

null method of measurement

adjust one or several quantities with known equilibrium relationship (or known value) with the measured value, and use the balance method to determine the measurement method of the measured value. For example, measure the impedance with an electric bridge and a zero pointer

result of a measurement

the measured value obtained from the measurement

note: ① when using the term measurement result, it should be clear whether it is a standard value, an uncorrected result, or a corrected result, and whether several observations have been averaged

② the complete description of the measurement results should include: information about the measurement uncertainty and information about the corresponding influence value

[measuring instrument] indication [of a measuring instrument]

the measured value provided by the measuring instrument

note: ① the indicated value is expressed in the measured unit. The value appearing on the scale (sometimes called direct indication, direct reading or scale value) must be multiplied by the instrument constant to obtain the indicated value

② the meaning of the term indicated value can sometimes be extended, including the quantity value recorded by the recording instrument or the measurement signal in the measurement system

uncorrected result

uncorrected measurement results with systematic errors

note: if only one indication is involved, the uncorrected result is the indication

corrected result

the measurement result obtained by correcting the uncorrected result in consideration of the existence of systematic errors

accuracy of measurement

synonyms: measurement accuracy

the consistency between the measured result and the [agreed] true value

repeatability of measurement

the consistency between the results of multiple consecutive measurements on the same measured object under the same measurement method, the same observer, the same measurement instrument, the same place, the same working conditions and repeated conditions in a short period of time

note: measurement repeatability can be quantitatively expressed by the dispersion of results

reproducibility of measurement

when each measurement is carried out under the conditions of changing the measurement method, observer, measuring instrument, place, working conditions and time, the consistency between the same measured results

note: ① the report of measuring reappearance requires that the changed conditions be explained

② measurement reappearance can be quantitatively expressed by the degree of dispersion of the results

uncertainty of measurement

represents an estimate that the measured true value is within a certain range

note: measurement uncertainty generally includes multiple components, some of which can be estimated based on the statistical distribution of the results of the measurement column, and can be characterized by standard [bias], while other components can only be estimated based on experience or other information

absolute error

the measured [agreed] true value is subtracted from the measurement result

note: ① this term is also applicable to the indicated value; Uncorrected results; The result has been corrected

② the measurement error of the known part can be compensated by applying appropriate correction, and the absolute error of the corrected result can only be characterized by uncertainty

③ absolute error has a sign, which should not be confused with the absolute value of error, which is the modulus of error

relative error

absolute error divided by the measured [agreed] true value

random error

in the process of multiple measurements being measured, its change is part of the unpredictable measurement error

systematic error

it is part of the predictable measurement error to maintain a constant or its change in the same measured multiple measurement processes

note: systematic error and its causes can be known or unknown

correction

is a value added to the uncorrected measurement result by algebraic method to compensate the systematic error

note: ① the modulus of the correction value is equal to the modulus of the system error, but the sign is opposite

② because the systematic error cannot be accurately known, the corrected value contains uncertainty

correction factor

the numerical factor multiplied by the uncorrected measurement result to compensate for the systematic error

note: since the systematic error cannot be accurately known, the correction factor contains uncertainty

arithmetic mean

the algebraic sum of N measurements of a quantity divided by n

residual error

the difference between a measured value I in the measurement column and the arithmetic mean of the column. Residual I is calculated by the following formula:

standard deviation of a single measurement in a series of measurements

a parameter representing the dispersion of the results obtained from n measurements of the same measured value. More:

the standard [deviation] of a single measurement in the measurement column is calculated according to the following formula:

where: n-the number of measurements (should be sufficiently large); DJ - the difference between the measured value and the measured [agreed] true value

in the actual limited number of measurements, use the residual I instead of Di, and calculate the estimated value of the standard [deviation] s:

standard deviation of the arithmetic mean of the series of measurements

a parameter representing the dispersion of the arithmetic mean in the independent measurement column of the same measured value. The standard [deviation] SR of the arithmetic mean value of the measurement column is calculated as follows:

where: S-the standard [deviation] of a single measurement in the measurement column; N-number of measurements

weighted arithmetic mean

in the multi group measurement of a certain magnitude, considering the weight of each group of measurement results, what is a good service to calculate this column of measurement results? What is the arithmetic mean of good service

weighted arithmetic mean LP is the quotient obtained by dividing the sum of the products of the arithmetic mean (L1, L2, LN) of the measured values of each group and the corresponding weights (P1, P2, PN) by the sum of the weights P1 + P2 + PN). The formula is:

note: the proportion of each measured value in the calculation of measurement results is expressed by the number of weight (P). The greater the weight, the greater the degree to which the calculated measurement results depend on the measured value

standard deviation of weighted arithmetic mean

in multi group measurements, a parameter characterizing the dispersion of weighted arithmetic mean in measurement results. For example:

when the difference between the arithmetic mean of the measured values in each group and the weighted arithmetic mean of the measured values in multiple groups is known to be V1, V2, VN, then

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