With Latin roots, the meaning of the word measurement refers to the action and the result of measuring, with lexical elements such as "metiri" which means to measure, and the suffix "tion" which means action and effect. It refers to the comparison that exists between a certain quantity and another, to show whether the mass or set to be measured accommodates that magnitude. It can be said that making a measurement is based on determining or specifying what magnitude there is between the dimension or volume of a body or element and a unit of measurement.
For this to happen, there must be an equality of magnitude between the size of what is measured and the chosen pattern, taking an object and an already established unit of measurement as a reference point.
What is measurement
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Measurement is the process by which a certain pattern is compared with a unit of measurement, and thus it is possible to know how many times this pattern is contained in that magnitude.
It is the process of assigning values to elements or phenomena of great importance within the framework of a geographical approach. This also consists of assigning symbols or numbers to characteristics of organisms or individuals in the existing world in such a way that it describes them according to clearly defined rules.
One of the most authentic examples of the meaning of measurement is the process for measuring earthquakes, which is elaborated by means of a machine or device that aims to previously detect when a seismic event is approaching; and the aspects that can be calculated from this are its magnitude and intensity, for which different scales are used, one of the most popular is Richter's, which seeks to determine the cause of said tremor; and Mercalli, which focuses on the effect caused by the event.
What is measure
According to its definition, it is a procedure of science that occurs when comparing a selected model with a phenomenon or object whose physical magnitude is to be measured to find out how many times that pattern is contained in that magnitude.
In addition to the above, it can be said that measuring is assigning symbols, numbers or values to the properties of objects or events according to the established rules.
What is measuring in physics
In physics, measuring is the comparison of the magnitude of what is measured, called the measurand, with the unit, that is, if a table has the amount of length three times greater than the rule that is taken at that time as a unit, it is It says that the measure of the table is 3 units, or also that the table measures three rulers.
Physics (physical magnitude) is known as the property or quality of a physical object or system to which different values can be assigned as results of a qualitative measurement. The physical magnitudes are quantified using the pattern that has that magnitude very well defined, taking as a unit the amount of that property that the object or pattern possesses.
Measurement types
As noted above, the concept of measurement is a scientific process used to compare the measurement of one object or phenomenon with another.
Measurement types allow you to calculate the number of times the model or pattern is contained in a given quantity. It is important to note that the measurements can be wrong by not using the appropriate instruments in this process.
The types are:
Direct measurement
It is the one that is done using a device to measure the magnitude, for example, to measure a length of some object you can use a caliper or a tape measure.
There are possibilities that a direct measurement cannot be carried out, because there are variables that cannot be measured by direct comparison, that is, with patterns of the same nature, because in comparison the value to be measured is very large or very small and depends on the obstacles by its nature, etc.
Indirect measurement
An indirect measurement is one in which the value of a dimension is obtained from direct readings of other dimensions and a mathematical expression that relates them. Indirect measures calculate the value of the measure by means of a formula (mathematical expression), after calculating the quantities involved in the formula by means of direct measures. Indirect measures also result from calculation when a quantity is a function of one or more indirect measures.
Reproducible measurement
They are those that when making a series of comparisons between the device used to measure and the same variable, the same result is always obtained. For example, if the measurement of the base of a table is carried out several times, the same result will always be obtained. This type of measurement are procedures that are not destroyed or produce significant alteration in the physical system which is being measured.
There are other types of measurement, one called statistical measurement, refers to those measurements that when making a series of comparisons between the same variable and the device used for the measurement, different results are obtained each time, for example determining the number of users who they use a web page daily.
Measurement tools
They are devices used to measure the physical magnitudes of different phenomena, such as, for example, with a vernier, the outside diameter of a nut can be measured.
The main characteristics of an instrument to perform measurements are:
- Resolution.
- Accuracy and precision.
- Error.
- Sensitivity.
- Linearity
- Range and scale.
Some measuring instruments according to the magnitude to be measured are:
To measure length
- Ruler: Rectangular instrument of very little thickness that can be made of different types of materials, but very rigid, it is used to draw lines and measure the distance between two points.
- Folding rule: It is used to measure distances with the appreciation of 1 mm. In this instrument, the zero coincides with the end, so it must be measured starting from there and its length of 1 m or 2 m.
- Micrometer: Precision instrument to measure lengths with an accuracy of hundredths of millimeters 0.01 mm, with the ability to perform these measurements as it has a precision screw with a graduated scale.
To measure angles
- Brackets.
- Goniometer.
- Sextant.
- Conveyor.
To measure masses
- Balance.
- Scale.
- Mass spectrometer.
To measure time
- Calendar.
- Chronometer.
- Clock.
To measure pressure
- Barometer.
- Pressure gauge.
To measure flow
Electrical measuring instruments
This type of instrument is used to put into practice a method that allows calculating electrical quantities. These measurements can be made based on electrical functions, using properties such as flow, pressure, temperature, or force.
There are electrical currents that can be recorded and measured, for this reason there are many advantages that must be used correctly to measure electricity, especially in devices designed with a pulsating or continuous alternating current.
Some instruments used for electrical measurement are:
Ammeter
This device is used to measure the strength of electric current flowing through the interior in amperes (A), that is, how much current is in a circuit or how many electrons travel in unit time.
Multimeter or tester
This instrument is made up of several in one, it is used to measure electrical quantities, selecting them through a knob. Its functions are to measure voltage or voltage, current intensity, electrical resistance, among others.
Voltmeter
It is used to measure voltage or electrical tension, its basic unit is the measurement in volts and their multiples, which are the kilovolt, megavolt and submultiples such as the microvolt and the millivolt.
Oscilloscope
This instrument is capable of presenting its results through graphic representations, in which the electrical signals can be modified over time. They facilitate the visualization of unusual and transient events, as well as electrical and electronic circuit waves.
Different existing measurement systems
It is known as a measurement system, the group of elements, things or rules that are related to each other to fulfill a function that is to measure. For this reason this system is also known as the unit system, considered a set of uniformed and standardized units of measurements.
Among the main measurement systems are:
The metric system
According to its history, it was the first system of measurements proposed to unify the way in which the elements were counted and measured. Its basic units with the kilogram and the meter, in addition to the multiples of units of the same type, must always increase on a decimal scale, that is, from ten to ten. This system has evolved over time, has been restructured and expanded to become the Alfaro International System, known to all today.
International System of Units
Known by its acronym SI, it is currently the most popular in the world, it was accepted and adopted by all the countries of the world with the exception of Burma, Liberia and the United States.
It is a derivative of the metric decimal system, for this reason it is known as the metric system. Its basic units of measurements were established in the XI General Conference of Weights and Measures in 1960 and these are: meter (m), second (s), kilogram (kg), ampere (A), candela (cd) and kelvin (K), in addition to the mole to measure chemical compounds.
This system of units is fundamentally based on physical phenomena, its units are an international reference that are used as a basis in the development of measurement instruments and tools.
Cegesimal system
Also known as the CGS system, it is made up of the units of centimeter, second and gram, hence its name.
Created in the 19th century by the German physicist and mathematician Johann Carl Friedrich Gauss in order to unify the units used in the different technical and scientific fields.
Thanks to this cegesimal system, some physical formulas are easier to express, the objective proposed by Gauss was achieved as well as the expansion of certain physical and technical terms, it was possible to other areas of knowledge.
Natural system
The natural system of units or Planck units, was born under the proposal of Max Planck at the end of the 19th century with the aim of simplifying the way in which physical equations are expressed or written.
This set of units includes the measurement of fundamental quantities such as mass, temperature, length, time and electric charge.
There are other measurement systems used in different fields of science such as:
- Units used in Astronomy.
- Atomic units.
- Units of mass.
- Units of measurements of energy.
Various measurement tools
Measurement tools are instruments that allow the comparison of the magnitude of a piece or object, generally with a standard established in the national system of units.
Some of the most used measurement tools are:
- Measuring tape.
- Ruler.
- Caliber.
- Dial gauge
- Interferometer.
- Odometer.
What is temperature measurement
Temperature measurement is based on any physical property of a substance that always has the same value for a given temperature and that, within a certain temperature range, varies approximately linearly with temperature. Properties of this type that are used in practice are: the volume of a liquid, the pressure of a gas whose volume remains constant or the electrical resistivity of a metal.
Measurement scale
The scale of measurement of a characteristic has consequences in the way of presenting the information and the summary. The measurement scale also determines the statistical methods used to analyze the data. Therefore, it is important to define the characteristics to be measured.
Temperature measurement scale
To be able to express the temperature of a body numerically, a scale must be previously established, and for this the first thing to do is choose two fixed points, that is, two well-known and easily reproducible physical situations at whose temperatures several numerical values are assigned. arbitrary.
Currently the scales used for temperature measurement are:
- Celsius scale.
- Fahrenheit scale.
- Kelvin scale.
- Rankine scale.
Statistical measurement scale
In statistics, data is studied. The data is the representation of the attributes or variables that describe the facts, when they are analyzed, processed and transformed into information. To do this, you need to compare the data against each other and against the benchmarks. This process of comparison requires scales of measurement.
For the data to make sense it is necessary to compare them. And to compare them, the measurement scales should be used. These scales have different properties depending on the characteristics of the data to be compared.
The most used statistical measurement scales are the following:
- Ordinal scale.
- Nominal scale.
- Interval scale.
- Ratio scale.
Measurement errors
The errors in the measurement not only depend on the procedures that are applied, they can also occur because the calculated derivation will not always be perfect. In measurement there is never 100% accuracy, some appear naturally and become so persistent that the exact amount cannot be established and the reasons will never be found. There are several types of measurement errors that must be taken into account in order to restore any measurement.
Types of measurement errors
In a company or industry, keeping a low margin of error is a big challenge. But it's not just human errors that cause an industrial disaster. Certain devices can be disrupted by systemic or environmental conditions. One way to combat this notion is to inspect the true measurement model by focusing on the error component.
The types of errors are:
- Gross errors.
- Measurement error.
- Systematic errors.
- Instrumental errors.
- Environmental errors.
- Final mistakes.
How to do area and distance measurement
In surveying, the measurement of areas and distances are carried out based on a survey of angles that can be read with precision through a series of very refined equipment, the length of a line must be measured to complement the measurement of the angles in the location of the points.
There are different methods for measuring distances, if it is done in steps, the instruments are, the odometer, the rangefinder, the common steel tape, the invar tape and tachymetry (stay).
To carry out this measurement with electronic instruments, the Global Positioning System (GPS) is used.
