The MKS system is a method of measurement in which the meter, the kilogram and the second are used as the units that serve to express the quantities that have to do with length, mass and time. It is the origin of the current international system of units and its name, MKS, is an acronym that arises from the union of the three basic units that make it up.
The standards to define the value of a meter and a kilogram can be found in the international office of weights and measures, because both quantities are based on physical objects. While one second was established as 1 / 86,400 of an average solar day.
Prototype of a standard kilogram of dough. Source:, via Wikimedia Commons.
The use of the MKS is relevant because it was one of the first magnitude systems that followed a decimal logic and that were adopted internationally in a standardized way. This improved the accuracy achieved in all sorts of disciplines, and laid the foundation for modern measurement methods.
History
The measurement systems date back to the 3rd or 4th centuries BC. From very early in the history of civilizations, measurements were necessary for agriculture, construction and the economy. However, the units used by the first cultures depended on each region or even each community.
In the Babylonian or Egyptian Empire there are records that to measure the length of an object the forearm, hand or fingers could be used as reference systems.
The time was calculated by the periods of duration of the movement of the Sun or the Moon. While to calculate the capacity of a container, it was filled with seeds that were then counted.
MKS first appearance
The metric system was created for the first time in 1668 and at first it was only adopted in France, as a result of the French Revolution. The system was based entirely on the meter and was therefore called the metric system (MKS).
In it the unit that refers to mass is the kilogram and the unit of time is the second. The spread to other countries did not take long and its expansion occurred quickly.
On the other hand, the Scottish scientist James Clerk stated, during the last years of the 19th century, that the CGS method used up to now was not sufficiently precise when it comes to defining the magnitude values of electrical and magnetic events. One of the errors he noticed was that the measurements used were too small and therefore not useful for analysis.
For this reason, in 1901 the Italian professor, engineer and electrician Giovanni Giorgi developed another system based on the MKS, where the units of length, mass and time are the meter, the kilogram and the second respectively, but a fourth value was added to the system, which was the amp.
The Italian presented his idea to the Italian Electrotechnical Association (AEI), where he assured that adding a new unit for the magnitudes at the electrical and magnetic level was vital to be able to express their correct values.
This variant was also known as the Giorgi measurement system.
Present
By 1948 many books were still written using the CGS system of units. It was in 1950 when the MKS system that included the fourth basic unit was recognized as the international standard and the International Electrotechnical Commission recommended the use of amperes as a fundamental measure.
An important feature of this system are the exact decimal expressions, which made it add more followers and be adopted by many countries, including India, where the system was introduced in 1957.
Then, in order to achieve some uniformity throughout the world, the General Confederation of Weights and Measures recommended a unified system in 1960. This is the International System of Units (SI), and it is the one used in most countries. nowadays.
It is based on the use of seven basic units: the meter, the kilogram and the second, present in the MKS system, plus the addition of the kelvin, the ampere, the candela and the mole.
Other systems
As you can see, throughout history there have been several types of unit systems: mainly the FPS, the MKS and the SI.
The FPS system was created in England and is based on the foot, the pound and the second as units to measure distance, mass and time respectively. Currently this is known as the System of Traditional Units, and is used in countries such as the United States.
The International System of Units (SI) is the one that replaced the MKS and was essentially based on the metric. It has seven basic units. Finally, the cegesimal system (CGS) is based on the centimeter, the gram and the second. It was a system proposed by Johann Carl Friedrich Gauss in 1832.
Basic units
The basic quantities vary according to each system. They are also known as fundamental units. In the MKS there are three: meter (for length), kilogram (to express quantities of mass) and second (to calculate time).
In SI, the Kelvin is the basic unit for calculating the amount of temperature. The metric system accepts this unit as the official one.
Derived units
Then the derived units appear, such as velocity, acceleration, etc. All of them can be reduced to a combination of the basic ones of length, mass and time. That is, they originate from the basic units of the MKS, which coincide with those of the International System of Units.
For example, in both methods the speed is expressed in meters per second. Power is represented by watts, which is equal to one joule per second. Finally, acceleration is measured in meters per second squared.
Conversions
The units of each metric system can be converted to units of any other. For this, calculations are carried out through the processes established in the conversion tables, which are those that allow us to know the equivalences between magnitudes.
The process is as simple as doing a multiplication by a fraction, and thus the equivalent measure is obtained in another system of units.
References
- Bakshi, U., Bakshi, K., & Bakshi, A. (2007). Electrical measurements and measuring instruments. Pune, India: Technical Publications Pune.
- Bhatt, B., & Vora, S. (2007). Stoichiometry. New Delhi: Tata McGraw-Hill.
- Edwards, D. (2014). Electronic Measurement Techniques. Burlington: Elsevier Science.
- Kidwell, W. (1969). Electrical instruments and measurements. New York: McGraw-Hill.
- The Meter-Kilogram-Second (MKS) System of Units - Maple Programming Help. Recovered from maplesoft.com