The reproducibility of a measurement is called accuracy. If all the measures are very similar, we say that the determined value is well known. If we cannot get very similar measures, we cannot say that the value is well known, but we say that the measures are imprecise. A set of measurements is accurate when all measurements are very similar, i.e. when there is a small range of values. Second, it is important to distinguish between accuracy and accuracy for measurements. Contrary to general usage, these words are not interchangeable. They are not mutually exclusive. Precision is the term used in the scientific context for the compliance of a given measure at fair value. An exact value is a real value.
Precision is the term used in science to describe the reproducibility of a measurement. The more accurate a measurement, the closer each value is to repeated reading. The measurements are much more precise than complete. Given the constraints of most measurement instruments, especially those used in introductory chemistry, measurements are generally only safe for a few significant numbers. Within the limits of these devices, repeated measurements are very often reproducible. On the other hand, for the same reasons, no measure is entirely accurate. We simply cannot „see“ all possible decimals with a measurement tool. When scientists study new phenomena, there are no repositories to determine whether the measurements are accurate. In this case, a scientist does not have the ability to tell if a value is correct, unless there is precision on the measurement repeated by him or others.
Therefore, there is always a degree of error in the accuracy of a measurement. This error is called accidental error because the measurement is as likely as it is high or low. Sometimes it`s an indefinite mistake, because it`s only the fault of the limitations of the measurement tool. The last significant number of a measured amount contains this random error and may be equal or small. A measure may also present a systematic error. This is the result of an incorrect measurement or an inappropriate measurement instrument. A systematic error is simply wrong. This is sometimes a determining error because it can be corrected using a measuring device that works properly or the right choice of device.