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1. Estimation of measurement errors

The ultimate goal of any measuring is finding the result of
the measurement as an evaluation of true value of measured
quantity. Positive assessment of measurement is its accuracy, that
characterizes proximity of measurement result to the true value.
The closer result is with the true value, the more accurate
measurement is and vice versa.
It is known that for measurements of one value, which are
sufficiently accurate, results of individual measurements differ
from each other, and therefore contain error.
Measurement error is the difference (x-a) between the
result of the measurement (x) and its true value (a), which is being
measured. Measurement error is usually unknown, as well as true
value is. Therefore, one of the main tasks of processing of results
of experiment is to evaluate the true quantity value.
True value of physical quantity is a value that perfectly
reflects quantitative and qualitative properties of the object.
According to the results of studies (results are repeatedly measured
and number of values is obtained, each of which contains some
unknown error) it must be determined the approximate quantity
value with smallest error.
Measurement errors and their types
Quantitative property which is displayed by physical
quantity, is determined by the value of physical quantity. Before
the measurements there is certain value of physical quantity, which
would be possible to estimate by appropriate numerical value. This
value is called true value.
Absolute error of measurement Δ is called the deviation of
measurement result from the true value of the measured quantity:
Δ = x – X, (1.1)
where x – result of measurement;
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