What is a scale?This is a sign system for which a mapping is specified. The element of the scale is mapped to real objects. We can say that the scale of measurements is a graduated ruler, on which values of any value (distance, temperature, pressure) are plotted. The problem associated with ensuring high quality products is inextricably linked with the quality of measurements. If the latter does not meet modern requirements of technical progress, there is no way to achieve the appropriate quality products. The next step will be a detailed description of what the measurement scale is for. The types of measurement scales will also be discussed in detail in this article.
As it was said earlier, if we successfully solveissues that relate to the accuracy of measuring the quality parameters of materials and other products, as well as the maintenance of modes in production technology, the quality of products will significantly improve. In simple words, quality control is the measurement of all parameters of technological processes. The results of their measurements are needed to control the process. The more accurate the results, the better the control.
The measurement state has the following main properties:
Reproducibility of results is proximitymeasuring results of one magnitude that were obtained in different places, using different methods and means, at different times and different people, but under the same conditions (humidity, pressure, temperature).
The convergence of the measurement results is whenthe results of measurements of a single value that were carried out repeatedly using the same means, by the same method, under the same conditions, with the same thoroughness, are close.
Any measurement is carried out using the appropriate scales.
It has already been said that a scale means a number of certain marks that are ordered. This series corresponds to the ratio of the values of the measured value following one another.
What is a measurement scale? This is a sequence of values of quantities that have a different size and are of the same name. It must be accepted by agreement.
In practice, five types of scales are used:
The places that the values occupy in such a scale,are called ranks. The scale itself is also called rank or non-metric. In it, all the numbers are ordered according to their places. Intervals between them can not be accurately measured. This scale makes it possible not only to establish equality or inequality between the measured objects, but also to determine the nature of inequality in the form of logical judgments such as "more and less", "worse and better".
Using the scale of order can be measuredIndicators that are qualitative, but do not have strict quantitative measures. Widespread use of such scales in psychology and pedagogy, as well as sociology.
It differs from the interval scale by a strict determination of the position of the zero point. For this reason, it does not limit the mathematical apparatus used in the processing of the results.
What is a relationship scale?It measures the quantities formed as the difference of numbers, which are measured by the scale of intervals. Thus, the calendar time is counted on the interval, and the intervals of time - on the scale of relations.
With this type of measurement, anyvalue is an experimental definition of the ratio of this same quantity to that of the same, which is taken as unity. When measuring the length of an object, you can find out by how many times it is greater than the length of another object, which is taken as a unit of length, for example, a meter ruler. If only the ratio scales are used, then a more specific, narrow definition can be given to measurement: the measurement of any quantity is the finding by experience of its relation to the corresponding unit.
This scale is also called nominal.It is the simplest. The numbers in it play the role of labels. They are needed in order to detect and distinguish the objects under study. The numbers that make up this scale are allowed to be swapped. There are no "less-than-more" relations in it. For this reason, some think that its application should not be taken for measurement. Using the name scale, only a small number of mathematical operations can be performed. For example, you can not subtract and add its numbers, but you can calculate how many times a certain number occurs.
This is a type in which numbers are not simplyordered by ranks, but also separated by certain intervals. A zero point in this scale is chosen arbitrarily. This distinguishes her from the relationship scale. As examples, we can cite calendar time (in different calendars the beginning of the calculation of years was established for some random reasons), the potential of the electric field, the temperature, the potential energy of the lifted cargo.
The results obtained by measuring from thisscale, can be processed by any mathematical method, except for the definition of relations. The data that the scale shows, answer the question "how much less or more?", But do not give the opportunity to affirmatively say that one of the values of the investigated quantity is somehow smaller or larger than the other. For example, if the room temperature rose from 10 degrees to 20 degrees, you can not say that now it's twice as warm.
Often the magnitude of something is measured directly.For example, directly count the number of defects in products, the number of units of output, the number of students present at the lecture, how many years have passed, and so on. Making such measurements, on the scale, the exact absolute quantitative values of what is measured are noted. The scale of absolute values has exactly the same properties as the scale of relations. The only difference is that the values indicated on the first are absolute, not relative.
The results obtained after the measurement on this scale are the most reliable and informative. They are very sensitive to inaccuracies in measurements.
Thus, it became clear that such a scalemeasurements and for what it is used. As it turned out, she is not alone. There are five, and each is used to measure certain quantities. If earlier it seemed that the scale should measure only physical quantities, then it turns out that in such sciences as psychology and sociology, there are also scales that measure numerical values. In fact, the psychological test is also such a scale.
The measured quantity is called a variable,than the measurement is done by the instrument. As a result, data or results are obtained that can be of different quality and refer to one of the scales. Each of them puts restrictions on the use of some kind of mathematical operations.
