People often face the finding of aphysical quantity. In this case, they talk about measuring something. This term comes from a science called metrology. What is a dimension?
A measurement is a process of determiningof any physical quantity by means of measuring instruments by experimental means. The result of the measurement process is the value in the accepted units, which is called valid.
The measurement principle is a physical phenomenon or several such phenomena that are used as the basis for measurements. For example, measuring the temperature with the help of a thermoelectric effect.
What is the measurement method?This is such a combination of methods of using measuring instruments and their principles. And what is a measuring tool? These are those technical means that have metrological properties, corresponding to the norms.
So, what is a dimension whose definitiongiven above, it is understandable. But there are also types, the classification of which is carried out, based on how the measured value depends on the type of equation, time, conditions that determine the accuracy of the results of the measurement, as well as the ways in which these results are expressed.
Paying attention to the dependence of a quantity that is measured on time, two types of measurement can be distinguished:
The method of obtaining the results, which is determined by the type of the equation for the measurements, divides the measurements into direct and indirect, as well as joint and cumulative.
Under the conditions that determine the accuracy of the result, you can divide the measurements into three classes:
1. Measurement accuracy, which is the maximum. This includes measurements of high and reference accuracy.
2. Control-checking. Their error with some probability should not be higher than some given value.
3. Technical. These are measurements where the error of the final value is determined by the characteristics of the means used in the measurement process.
By the method of expressing the results of measurements, it can be divided into absolute and relative.
Unity of measurement means consistencysizes of all quantities. This is obvious if we pay attention to the fact that one and the same quantity can be measured both by direct and indirect methods. Such coherence can be achieved by creating a system of units. The first such system appeared in the late 18th century. It became the well-known metric system. And the first scientifically grounded system of units was the system proposed by Karl Gauss. It was based on three units: second, millimeter and milligram. It was on the basis of such an absolute system that a modern system of units was built.
The unit of measurement is the specific value,which is defined and established by agreement. With it, other quantities of the same kind are compared to express their size with respect to the indicated magnitude.
Each measured physical quantity mustcorrespond to its own unit of measurement. Thus, individual units are necessary for measuring speed, length, volume, weight, distance and so on. Each unit can be determined by selecting a standard. The system of units becomes more convenient if it contains only a few units that are chosen basic, and the rest are determined already through them. The standard unit of length is the meter. Based on this, one square meter is considered a square meter, the unit of speed is a meter per second, and the unit of volume measurement is a meter in a cube.
What is the measurement error?This term refers to the deviation of measurement results from the actual or true value of a quantity that is measured. The true value of the quantity is unknown. It is used only in theoretical studies.
Sometimes the question "what is the measurement error?" Can be heard as a response by another definition - "measurement error". But it is better not to use it, because it is less successful.
The systematic error in measurements ispart of the error of the final measurement result, which remains constant or changes regularly with repeated measurements of the physical quantity. The nature of the measurement divides the systematic errors of several kinds.
Instrumental error is called the component of the measurement error, which is due to the error of the instrument used.
The error of the measurement method is the component, which is due to the imperfection of the method that is adopted for the measurement.
What is the result of the measurement? This is the value of the physical quantity, which is obtained by measuring it.
A defective measuring result is the value of the value that was obtained during the measurement before it was corrected to take into account systematic errors.
The corrected result is the value of the value that was obtained during the measurement and refined by introducing the necessary corrections.
The convergence of the measurement results is the proximity of the results, which were carried out repeatedly using the same means, by the same method and under the same conditions.
What is the reproducibility of the results?This is the proximity to each other of the results that were obtained in different places, different means and operators using different methods, but which were brought to the same conditions.
A series of measurement results is a sequence of values of the same value that were obtained as a result of a series of measurements that follow one another.
Today you can measure not only physicalvalues. Since the era of computer technology has come, information is used everywhere in a digital form. It is also possible to measure it. What is the measurement of information? This is the definition of the number of data that is expressed in terms of its units. The reference unit for measuring information is a bit, which is the amount of information that occurs with equiprobable events. For example, tossing a coin can lead to two equally probable outcomes. The loss of one of the parties contains information in the volume of one bit.
The name of this unit of measure comes fromthe abbreviation of the term "binary number". This is a number that can take only two values - one or zero. Such numbers I use in all kinds of computer technology to represent any information. Since a bit is a very small unit of information measurement, it is customary to use larger ones. These are bytes, kilobytes, megabytes, gigabytes, terabytes, and so on.
The volume that takes up any character entered from the keyboard is equal to one byte. This is 8 bits.
Thus, all concepts were considered,used in the measurement. This is a system of measurements, error and its types, results. It was considered what a unit of measurement, and what these units are. All this is necessary for people who are dealing with science, computing, and just to broaden their horizons. After all, in the age of information technology, the wisdom is that knowledge is power.
