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The accuracy of measuring quantities is the ability to streamline a person’s existence and its environment. It would be impossible to imagine a life in which the usual and established concepts of time, length or mass would be absent for all of us. However, besides the fact that they need to be able to be distinguished, it is equally important to learn how to determine and calculate distances and segments, weight, speed of movement of objects, the course of time intervals. Over the thousand-year history of existence, mankind has gained a lot of invaluable knowledge and has managed to systematize them into separate sciences.
Concepts and notation - the basics of metrology
Metrology is a teaching that helps to understand the measurement of different quantities. It makes it possible to understand what a measure, unity and standardization of quantities are, defines such concepts as measurement accuracy, error, introduces a variety of measuring instruments and tools.
The measurement process is associated with the determination of data regarding a particular quantity through experiments, as well as the subsequent correlation of the obtained values with generally accepted standards and units. Thus, we can assume that the measurement accuracy directly depends on how close the data obtained as a result of the experiments are to the true values of the quantity, which, in principle, cannot be disputed and are an axiom.
Absolute inaccuracy
Scientists argue that measuring something absolutely right is practically impossible. The fact is that there are too many factors affecting the process of determining the value, independent of human actions. In this regard, metrology allows for the possibility of errors, which are inaccuracies obtained during the measurement process, as well as some kind of indicator that shows deviations from the generally accepted truth and norm.
The error may be systematic or random. It is practically impossible to exclude the former during the experiment, because this is such a factor that will distort the result each time, but a random error may be the result of a gross error or inaccuracy of analytical activity.
The probability of error can also be reduced by using more advanced methods and tools, minimizing the influence of external influences during the experimental determination of values. The use of hours can be considered an elementary example of reducing errors, if time is measured not in hours and minutes, but in fractions of a second, which allows electronic stop watches to be made.
Measure seven times ...
The need to obtain absolutely accurate knowledge of the quantities is due to the high technology of the modern world. If the first example of furniture was a roughly knocked-out toilet seat, the details of which were cut out by eye, then current technologies help to create elements of the same stools with an error of up to a millimeter. It is possible that such microscopic values are absolutely unimportant in a person’s daily life, but when the accuracy of measurement concerns science, medicine, production, it becomes a decisive factor in the success of an enterprise.
If you look closely, each person in the house has the simplest measuring instruments. Elementary examples of these are construction tape, ruler, kitchen or floor scales, steelyard, electricity, water, gas meters, different timers and clocks, thermometers and thermometers. Using the latter, one can once again demonstrate the methods and accuracy of measurement. So, a common alcohol thermometer installed in a room to determine the air temperature in a room has a scale divided by ten degrees, while a mercury thermometer designed to measure a person’s body temperature is divided into a tenth of a degree, which helps reduce the likelihood of errors during collection of patient history.
What is the length and how to measure it?
One of the most recognizable and definite quantities is length. Probably, initially a person measured the distance with the help of steps, now the units of measurement of distance are normalized. The world standard is a metric system where the highest value is measured in kilometers, conventionally divided into meters, centimeters and millimeters. There are also intermediate quantities (decimeters, micrometers), but they are often used only in highly specialized areas.
In order to determine the length, it is necessary to select a specific segment that will have a beginning and an end (points A and B), and so length is the value of the largest distance on the plane between these points. For measuring length, a lot of tools have been created from elementary, such as a centimeter and a ruler, to control and measuring equipment with a high degree of accuracy with minimal error.
Household appliances for measuring length
It is unlikely that an ordinary person will need to measure long distances, each of us knows approximately the length of our routes, you can clarify such data using a car speedometer, a sports and tourist pedometer, or even using a smartphone by downloading a special program into it.
At home, length measuring instruments are more often used for construction and repair. Construction roulette is what any man has in the pantry. It is a metal tape with a scale from 0 to 3, 5, 7.5, 30 meters with an additional centimeter and millimeter division applied on one or both sides of it. An alternative to simple roulette can be a laser range finder, with which you can calculate distances up to 250 m, in addition, it is easy to measure the length even by yourself. There are also models that display the area and volume of the room.
Calipers
A caliper measurement will give the most accurate result. This is a device that is used in industry and provides an opportunity to know the linear size of parts ranging in size from 0.1 mm to 15 cm with a minimum error. To determine how close the scale is to the true value, you can use such comparative methods - comparison with an already tested tool or with a finished part of a suitable size.
There are several types of this device, the principle of operation is similar, they differ in the length of the millimeter scale and the mechanism by which the measurement is actually performed. A caliper with a vernier is most difficult to work with, but this option makes it possible to minimize systematic errors. In a device with a dial or a digital screen, measurements are made electronically, and if the instrument is of good quality, its results are reliable with a high degree of probability.
Sophisticated technology
Even more sophisticated computer technology is the instrumentation used in industrial enterprises and in organizations involved in the installation of power lines, the laying of television, telephone and Internet cables. This technique copes with several functions at once. The main task is to measure the length of the cable, however, along the way, the device can detect errors in the operation of the wire, indicating the place of a power outage, which significantly minimizes the means and time required for repair work.
There are different classes of measuring instruments. The most elementary are manual installations with cable length counters, more complex options are able to calculate not only the length of wires, but also measure wide rolls with fabrics, paper, different types of cords. In addition to the fact that their use is advisable on production lines, the introduction of such equipment in warehouses and in large retail outlets is spreading.
How to embrace the immensity
Measuring time is also a complex and important task. In life situations, few people pay attention to the fact that personal watches can rush or lag a few minutes behind the generally accepted standard. However, public organizations and enterprises cannot afford such liberties, and therefore they compare time with indicators in state institutions, which, in turn, are guided by data obtained using satellites.
It is worth noting that such a thing as exact time is rather arbitrary. The time zones that the planet is divided into are objective in nature and are directly dependent on state borders, and sometimes on the political will of the governments of different countries.