No physical quantity can not be measured exactly.Each time, making any measurement and calling the result, it is possible to judge the absolute accuracy of the values obtained only with a certain probability.And the value of this probability is negligible due to the fact that any measured value is included in an interval, which determines the absolute error.
In general, under the error understanding deviation obtained from measured values of its true denomination.The realities of the world around us is such that no tool, no matter how accurate it may be, can not completely tell the exact value.And because the measurement of saying that the absolute error is defined by a range, and between its borders and is the measured value.
How determined interval in which the true value is measured value?The first option - it's accuracy.Depending on the technology of measuring its properties and characteristics occurs or that the error value.Of course, the higher the accuracy of the instrument, ceteris paribus, the more expensive it is, but at the same time and more accurate measurement results it provides the observer.Selection of measuring equipment and its accuracy depends on the requirements of the problem being solved.Not all calculations require high accuracy, and therefore it is important to choose the right tool so that the results do not affect the overall result of the measurement.
Another parameter that affects the accuracy - is the correct use of the instrument.Moreover, it plays a very important role in the measurement!Any person carrying out the measurements must be able to properly handle the measuring means.Otherwise, he risks not only get incorrect results, but did spoil the device.Therefore, before using measuring tools (especially the high-tech), it is important to read the instructions, understand the principle of the scheme and device settings,
and only then proceed to the measurements.
third option - a direct readout devices.If your device has a digital display, the absolute error on this criterion is zero.In the case where the device has a measuring scale, the measurement error increases asthe observer can simply remove the incorrect readings due to the physiological characteristics of a person.Typically, in such cases, the interval error rate is increased by dividing device.Last
key parameter associated with the method of processing the measurements.And first of all it depends on the correctness of rounding the resulting value.It should be noted that any rounding is initially distorts the true meaning, but then again during the procedure of processing the results is important to consider the impact on the real solution of the problem is the use of a particular method of processing values.
four parameters listed above - only the external, the most obvious factors influencing the formation of interval deviation value obtained from the real.The absolute error actually depends on a number of parameters, which, depending on the type of task, the influence of the medium, the type of device can have a tremendous influence on the measurement results.
In conclusion, how interconnected relative and absolute error.The first - is the ratio of the absolute error to the measured value.Therefore, if the absolute error - is of some importance with the same dimension as the measured value, the relative error shows what proportion of the error from the true value of the result.
