Measured value

of measured values are real numbers, whole numbers, or boolean values, which were won with a measurement by a certain regulation or proceeding in an attempt. As measured value from the actual observations, for example by averaging received size is also designated. Inthe rule is provided a measured value with a unit.

In particular measured values, which are represented by real numbers, are always faulted. One differentiates between statistic and systematic measuring errors. Statistic errors are in the experimental assembly and the Messapparaturen contained (for example noise in amplifiers) and can throughrepeated execution of the experiment to be reduced. Biased errors there against always change the result in the same measure and can therefore be out-counted, if them admit are. Such errors are for example wrong measuring of the devices, the change of the measured value by the measurement (voltmeter also too smaller Impedance) or an unsuitable experimental setup.

quality of a measured value

the quality or accuracy of a measured value can be estimated only objectively, if it is indicated together with its error and the Messunsicherheit admits is.

The statistic error can be described by means of the standard deviation.The fact is used that, if one accomplishes a measurement under same conditions several times the measured values, if only coincidental deviations from the Messbedingungen are present strew always around an average value.

Like that is a measurement, which intends acceleration due to gravity for (9.8 ± 1.0) m/s ² (thiscorresponds exactly to the literature value), nevertheless comparatively inaccurately, since from the measurement it can be only concluded that the “material value” lies with a certain statistic security within the range of 8,8 m/s ² to 10.8 m/s ². The material value is however unknown thereby. Usually becomes however as materialWorth so far the most exactly measured value or a literature value accepted.


See also: Measured variable, normal distribution

 

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