Special Feature Human Knowledge: Measurement

With the development of new tech- to exponential increase of possibilities machinery. This technology is used in The Convention was nology, international systems of units through the use of microcomputers many devices essential to our daily an achievement of French diplomat Talleyrand-Périgord were defined, such as the volt for volt- and so on. Automated control and lives, including cars, elevators, and air age, the ampere for electric current, operation based on measurement conditioners. D The was based upon the decimal system, the tesla for magnetic flux density, results are now the basis of was easier to understand than yards and feet, and was logical. It quickly became established in daily life after its and the candela, lumen, and lux for introduction, and also contributed to scientific progress. light. Multiple international systems existed, such as for temperature. Cel- When you cannot The Industrial Revolution and sius is the standard unit used in daily establishment of the metric system life in Japan, whereby the tempera- measure [something] Measurement was also essential in the ture at which ice melts is set as zero Industrial Revolution degrees Celsius, and the temperature . . . your knowledge The Great Global The Industrial Revolution, which occurred from the mid- at which water boils is set as 100 18th century through to the 19th century, was also consid- degrees Celsius. However, in the field is of a meagre and Transformation in ered a manufacturing revolution. It was epitomized by cot- of thermodynamics, the Kelvin is ton manufacturing technology, growth in iron production, Measurement that and the invention of steam-powered boats and trains. None used to measure absolute temperature. unsatisfactory kind. of this could have been achieved without the advancement This defines zero as the temperature William Thomson Began in the 18th of measurement technologies. at which all thermal motion of atoms and molecules ceases. It was intro- Known as an authoritative pioneer in thermodynamics, duced in the 19th century by physicist Century he introduced the concept of absolute temperature, and is Lord Kelvin (William Thomson). credited with discovering the Second Law of Thermody- Such measurement technologies led namics (Thompson's Principle). Just as the first Qin Emperor Earth over the six years from 1792 to created the Jialiang measurement 1798. To achieve this, they carefully With the introduction of the meter, the number of system, the West attempted to unify measured , a distance u international standard e p measurement standards. However, of 1,100 kilometers between Dunker- s units increased o Directly even into the 17th century, systems que in and in , l Measurement in Air Conditioning

C measuring varied throughout the world. Different in order to deduce the size of the In 1875, French diplomat Tall- Measuring room temperature Room temperature Measurement as a large control loop systems of measurement, such as the Earth. They then defined a meter as eyrand-Périgord helped to establish Indoor Outdoor temperature air conditioning unit Temperature yard, the pound, and Japan’s shaku- 1/40 millionth of the circumference of the , which 17 temperature and Refrigerant temperature kan system, were used in each coun- the Earth. The reason it was defined countries entered into. The meter thus maintaining it at a Overall air conditioning control try. In some cases, different weights thus was partially because it was close became an international standard certain level Revolution speed Indoor and measures were used according to to the length of the existing double- for measurement. Japan joined this An important factor in air conditioning is Indoor unit fan unit fan region or profession within the same cubit (based on the aforementioned convention, which now has over 50 constantly maintaining room temperature control at a certain level. A thermometer constant- country. The standardization of units unit based on the human body) and participating countries, in 1885. Angle ly operates inside of the air conditioner for Indoor was even a cause of conflict, making yard. Once an international standard for Flaps unit flap this purpose. Indoor air conditioning units control trade difficult, and impeding advance- Around the time when France measurement was certified with the control the fan revolution speed and the A ment in the fields of science and undertook this enormous task, in meter, more scientists started to see angle of flaps to ensure there is no varia- Indirectly measuring pressure industry. Japan, Inou Tadataka, who retired at the need for the unified measurement tion between the temperature measured and the set temperature. Similarly, outdoor Outdoor Revolution speed air conditioning unit the age of 50, began to study astron- of various phenomena in the natural air conditioning units control the overall Outdoor One meter is 1/40 Outdoor unit fan omy and . Between 1800 and world to achieve greater progress. millionth of the unit while checking fan revolution speed unit fan control 1818, he walked 35,000 kilometers to and the state of expansion valve opening. Aperture circumference of the Earth Compressors are equipped with Daikin’s Expansion measure the Japanese archipelago. He Expansion valve National Diet Library Digital Collections unique inverter (P20) to measure electric valves France was active in promoting the completed his Great Coastal Map of control current. These measurements are used Voltage need for a shared system of measure- Japan, the first ever accurate map of to operate functions that maintain room Air Compressor compressor ment for all countries. The French Japan. temperature at a certain level. control Electric current monarchy fell with the French Revolu- B Indirectly measuring Current measurement Measurement as a small control loop Indirect measurement (in each system of measurement) tion in 1789, and civil society headed location Location estimation towards modernization. There was Inou Tadataka’s map was used in later A Measuring pressure B Measuring rotational In the control system, sensors are usually used for measurements. an increasing opportunity to adopt a (measurement in two steps) displacement However, those are not always direct measurements. For example, generations due to its (measurement in three steps) more rational system of measurement precision pressure sensors are not typically used in small-to medium-sized Pressure sensor Rotor position sensor based on the metric system to replace Rotational air-conditioners, although refrigerant pressure value is indispensable The metric system was not estab- Refrigerant units of measurement such as yards Pressure Motor displacement for air conditioner’s control system. In many cases, pressure value lished in Japan at that time, and Voltage Waveform is calculated based on the measured refrigerant temperature. As yet and pounds. Winds of change swept the standard for measurement Temperature sensor analysis sensor another example, for motor control, rotor position is indispensable. Calculation Voltage drop Driving current the world with the Industrial Revo- was the shaku, which measured But rotor position sensors are not always used. In Daikin’s system, Refrigerant temperature lution in Britain and the American 30.304 centimeters. This is a map rotor position is estimated in three steps: measuring the resistance of Japan made in the Meiji Era Calculation Declaration of Independence. voltage drop, calculating the electric current, and then analyzing its (1868–1912), based upon Inou In France, scientists and politicians waveform. A range of technologies and expertise are used to reach the necessary measurement using high precision measurement, Tadataka’s map, which took 18 calculations, and analysis. united to measure the size of the years to complete.

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