1.
Termómetro
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A thermometer is a device that measures temperature or a temperature gradient. A thermometer has two important elements, a sensor in which some physical change occurs with temperature. Thermometers are widely used in industry to control and regulate processes, in the study of weather, in medicine, there are various principles by which different thermometers operate. They include the expansion of solids or liquids with temperature. Radiation-type thermometers measure the energy emitted by an object, allowing measurement of temperature without contact. Most metals are good conductors of heat and they are solids at room temperature, Mercury is the only one in liquid state at room temperature, and has high coefficient of expansion. Hence, the slightest change in temperature is notable when its used in a thermometer and this is the reason behind mercury and alcohol being used in thermometer. Some of the principles of the thermometer were known to Greek philosophers of two years ago. The modern thermometer gradually evolved from the thermoscope with the addition of a scale in the early 17th century, while an individual thermometer is able to measure degrees of hotness, the readings on two thermometers cannot be compared unless they conform to an agreed scale. Today there is a thermodynamic temperature scale. Internationally agreed temperature scales are designed to approximate this closely, based on fixed points, the most recent official temperature scale is the International Temperature Scale of 1990. It extends from 0.65 K to approximately 1,358 K, various authors have credited the invention of the thermometer to Hero of Alexandria. The thermometer was not an invention, however, but a development. The expansion and contraction of the air caused the position of the interface to move along the tube. Such a mechanism was used to show the hotness and coldness of the air with a tube in which the water level is controlled by the expansion and contraction of the gas. These devices were developed by several European scientists in the 16th and 17th centuries, as a result, devices were shown to produce this effect reliably, and the term thermoscope was adopted because it reflected the changes in sensible heat. The difference between a thermoscope and a thermometer is that the latter has a scale, though Galileo is often said to be the inventor of the thermometer, what he produced were thermoscopes. The first clear diagram of a thermoscope was published in 1617 by Giuseppe Biancani and this was a vertical tube, closed by a bulb of air at the top, with the lower end opening into a vessel of water
2.
Termometría
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Temperature measurement describes the process of measuring a current local temperature for immediate or later evaluation. Datasets consisting of repeated standardized measurements can be used to assess temperature trends, attempts at standardized temperature measurement prior to the 17th century were crude at best. For instance in 170 AD, physician Claudius Galenus mixed equal portions of ice and these early devices were called thermoscopes. The first sealed thermometer was constructed in 1641 by the Grand Duke of Toscani, fahrenheits scale is still in use, alongside the Celsius and Kelvin scales. Many methods have developed for measuring temperature. Most of these rely on measuring some physical property of a material that varies with temperature. One of the most common devices for measuring temperature is the glass thermometer and this consists of a glass tube filled with mercury or some other liquid, which acts as the working fluid. Temperature increase causes the fluid to expand, so the temperature can be determined by measuring the volume of the fluid, such thermometers are usually calibrated so that one can read the temperature simply by observing the level of the fluid in the thermometer. Another type of thermometer that is not really used much in practice, under some conditions heat from the measuring instrument can cause a temperature gradient, so the measured temperature is different from the actual temperature of the system. In such a case the temperature will vary not only with the temperature of the system. An extreme case of this gives rise to the wind chill factor. What is happening is that the wind increases the rate of transfer from the body. B, of course, is the thermometer, the practical basis of thermometry is the existence of triple point cells. Triple points are conditions of pressure, volume and temperature such that three phases are present, for example solid, vapor and liquid. For a single component there are no degrees of freedom at a triple point, therefore, triple point cells can be used as universal references for temperature and pressure. Under some conditions it becomes possible to measure temperature by a use of the Plancks law of black-body radiation. For example, the microwave background temperature has been measured from the spectrum of photons observed by satellite observations such as the WMAP. In the study of the plasma through heavy-ion collisions, single particle spectra sometimes serve as a thermometer
3.
Punto triple
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In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases of that substance coexist in thermodynamic equilibrium. For example, the point of mercury occurs at a temperature of −38.83440 °C. In addition to the point for solid, liquid, and gas phases. Helium-4 is a case that presents a triple point involving two different fluid phases. The triple point of water is used to define the kelvin, the value of the triple point of water is fixed by definition, rather than measured. The triple points of substances are used to define points in the ITS-90 international temperature scale. The term triple point was coined in 1873 by James Thomson, at that point, it is possible to change all of the substance to ice, water, or vapor by making arbitrarily small changes in pressure and temperature. Strictly speaking, the surfaces separating the different phases should also be perfectly flat, the gas–liquid–solid triple point of water corresponds to the minimum pressure at which liquid water can exist. At pressures below the point, solid ice when heated at constant pressure is converted directly into water vapor in a process known as sublimation. Above the triple point, solid ice when heated at constant pressure first melts to form liquid water, for most substances the gas–liquid–solid triple point is also the minimum temperature at which the liquid can exist. For water, however, this is not true because the point of ordinary ice decreases as a function of pressure. At temperatures just below the point, compression at constant temperature transforms water vapor first to solid. The triple point pressure of water was used during the Mariner 9 mission to Mars as a point to define sea level. More recent missions use laser altimetry and gravity measurements instead of pressure to define elevation on Mars, at high pressures, water has a complex phase diagram with 15 known phases of ice and several triple points including ten whose coordinates are shown in the diagram. For example, the point at 251 K and 210 MPa corresponds to the conditions for the coexistence of ice Ih, ice III and liquid water. There are also triple points for the coexistence of three phases, for example ice II, ice V and ice VI at 218 K and 620 MPa. For those high-pressure forms of ice which can exist in equilibrium with liquid, at temperatures above 273 K, increasing the pressure on water vapor results first in liquid water and then a high-pressure form of ice. In the range 251–273 K, ice I is formed first, followed by water and then ice III or ice V
4.
Agua
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Water is a transparent and nearly colorless chemical substance that is the main constituent of Earths streams, lakes, and oceans, and the fluids of most living organisms. Its chemical formula is H2O, meaning that its molecule contains one oxygen, Water strictly refers to the liquid state of that substance, that prevails at standard ambient temperature and pressure, but it often refers also to its solid state or its gaseous state. It also occurs in nature as snow, glaciers, ice packs and icebergs, clouds, fog, dew, aquifers, Water covers 71% of the Earths surface. It is vital for all forms of life. Only 2. 5% of this water is freshwater, and 98. 8% of that water is in ice and groundwater. Less than 0. 3% of all freshwater is in rivers, lakes, and the atmosphere, a greater quantity of water is found in the earths interior. Water on Earth moves continually through the cycle of evaporation and transpiration, condensation, precipitation. Evaporation and transpiration contribute to the precipitation over land, large amounts of water are also chemically combined or adsorbed in hydrated minerals. Safe drinking water is essential to humans and other even though it provides no calories or organic nutrients. There is a correlation between access to safe water and gross domestic product per capita. However, some observers have estimated that by 2025 more than half of the population will be facing water-based vulnerability. A report, issued in November 2009, suggests that by 2030, in developing regions of the world. Water plays an important role in the world economy, approximately 70% of the freshwater used by humans goes to agriculture. Fishing in salt and fresh water bodies is a source of food for many parts of the world. Much of long-distance trade of commodities and manufactured products is transported by boats through seas, rivers, lakes, large quantities of water, ice, and steam are used for cooling and heating, in industry and homes. Water is an excellent solvent for a variety of chemical substances, as such it is widely used in industrial processes. Water is also central to many sports and other forms of entertainment, such as swimming, pleasure boating, boat racing, surfing, sport fishing, Water is a liquid at the temperatures and pressures that are most adequate for life. Specifically, at atmospheric pressure of 1 bar, water is a liquid between the temperatures of 273.15 K and 373.15 K
5.
Kelvin
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The kelvin is a unit of measure for temperature based upon an absolute scale. It is one of the seven units in the International System of Units and is assigned the unit symbol K. The kelvin is defined as the fraction 1⁄273.16 of the temperature of the triple point of water. In other words, it is defined such that the point of water is exactly 273.16 K. The Kelvin scale is named after the Belfast-born, Glasgow University engineer and physicist William Lord Kelvin, unlike the degree Fahrenheit and degree Celsius, the kelvin is not referred to or typeset as a degree. The kelvin is the unit of temperature measurement in the physical sciences, but is often used in conjunction with the Celsius degree. The definition implies that absolute zero is equivalent to −273.15 °C, Kelvin calculated that absolute zero was equivalent to −273 °C on the air thermometers of the time. This absolute scale is known today as the Kelvin thermodynamic temperature scale, when spelled out or spoken, the unit is pluralised using the same grammatical rules as for other SI units such as the volt or ohm. When reference is made to the Kelvin scale, the word kelvin—which is normally a noun—functions adjectivally to modify the noun scale and is capitalized, as with most other SI unit symbols there is a space between the numeric value and the kelvin symbol. Before the 13th CGPM in 1967–1968, the unit kelvin was called a degree and it was distinguished from the other scales with either the adjective suffix Kelvin or with absolute and its symbol was °K. The latter term, which was the official name from 1948 until 1954, was ambiguous since it could also be interpreted as referring to the Rankine scale. Before the 13th CGPM, the form was degrees absolute. The 13th CGPM changed the name to simply kelvin. Its measured value was 7002273160280000000♠0.01028 °C with an uncertainty of 60 µK, the use of SI prefixed forms of the degree Celsius to express a temperature interval has not been widely adopted. In 2005 the CIPM embarked on a program to redefine the kelvin using a more experimentally rigorous methodology, the current definition as of 2016 is unsatisfactory for temperatures below 20 K and above 7003130000000000000♠1300 K. In particular, the committee proposed redefining the kelvin such that Boltzmanns constant takes the exact value 6977138065049999999♠1. 3806505×10−23 J/K, from a scientific point of view, this will link temperature to the rest of SI and result in a stable definition that is independent of any particular substance. From a practical point of view, the redefinition will pass unnoticed, the kelvin is often used in the measure of the colour temperature of light sources. Colour temperature is based upon the principle that a black body radiator emits light whose colour depends on the temperature of the radiator, black bodies with temperatures below about 7003400000000000000♠4000 K appear reddish, whereas those above about 7003750000000000000♠7500 K appear bluish
6.
Sistema Internacional de Unidades
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The International System of Units is the modern form of the metric system, and is the most widely used system of measurement. It comprises a coherent system of units of measurement built on seven base units, the system also establishes a set of twenty prefixes to the unit names and unit symbols that may be used when specifying multiples and fractions of the units. The system was published in 1960 as the result of an initiative began in 1948. It is based on the system of units rather than any variant of the centimetre-gram-second system. The motivation for the development of the SI was the diversity of units that had sprung up within the CGS systems, the International System of Units has been adopted by most developed countries, however, the adoption has not been universal in all English-speaking countries. The metric system was first implemented during the French Revolution with just the metre and kilogram as standards of length, in the 1830s Carl Friedrich Gauss laid the foundations for a coherent system based on length, mass, and time. In the 1860s a group working under the auspices of the British Association for the Advancement of Science formulated the requirement for a coherent system of units with base units and derived units. Meanwhile, in 1875, the Treaty of the Metre passed responsibility for verification of the kilogram, in 1921, the Treaty was extended to include all physical quantities including electrical units originally defined in 1893. The units associated with these quantities were the metre, kilogram, second, ampere, kelvin, in 1971, a seventh base quantity, amount of substance represented by the mole, was added to the definition of SI. On 11 July 1792, the proposed the names metre, are, litre and grave for the units of length, area, capacity. The committee also proposed that multiples and submultiples of these units were to be denoted by decimal-based prefixes such as centi for a hundredth, on 10 December 1799, the law by which the metric system was to be definitively adopted in France was passed. Prior to this, the strength of the magnetic field had only been described in relative terms. The technique used by Gauss was to equate the torque induced on a magnet of known mass by the earth’s magnetic field with the torque induced on an equivalent system under gravity. The resultant calculations enabled him to assign dimensions based on mass, length, a French-inspired initiative for international cooperation in metrology led to the signing in 1875 of the Metre Convention. Initially the convention only covered standards for the metre and the kilogram, one of each was selected at random to become the International prototype metre and International prototype kilogram that replaced the mètre des Archives and kilogramme des Archives respectively. Each member state was entitled to one of each of the prototypes to serve as the national prototype for that country. Initially its prime purpose was a periodic recalibration of national prototype metres. The official language of the Metre Convention is French and the version of all official documents published by or on behalf of the CGPM is the French-language version
7.
Anders Celsius
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Anders Celsius was a Swedish astronomer, physicist and mathematician. He was professor of astronomy at Uppsala University from 1730 to 1744 and he founded the Uppsala Astronomical Observatory in 1741, and in 1742 proposed the Celsius temperature scale which bears his name. Anders Celsius was born in Uppsala, Sweden on 27 November 1701 and his family originated from Ovanåker in the province of Hälsingland. Their family estate was at Doma, also known as Höjen or Högen, the name Celsius is a latinization of the estates name. As the son of a professor, Nils Celsius, and the grandson of the mathematician Magnus Celsius. He was a mathematician from an early age. Anders Celsius studied at Uppsala University, where his father was a teacher, in 1730, Celsius published the Nova Methodus distantiam solis a terra determinandi. He observed the variations of a needle and found that larger deflections correlated with stronger auroral activity. At Nuremberg in 1733, he published a collection of 316 observations of the aurora borealis made by himself, Celsius traveled frequently in the early 1730s, including to Germany, Italy and France, when he visited most of the major European observatories. In Paris he advocated the measurement of an arc of the meridian in Lapland, in 1736, he participated in the expedition organized for that purpose by the French Academy of Sciences, led by the French mathematician Pierre Louis Maupertuis to measure a degree of latitude. The aim of the expedition was to measure the length of a degree along a meridian, close to the pole, the expeditions confirmed Isaac Newtons belief that the shape of the earth is an ellipsoid flattened at the poles. In 1738, he published the De observationibus pro figura telluris determinanda and he was successful in the request, and Celsius founded the Uppsala Astronomical Observatory in 1741. The observatory was equipped with instruments purchased during his long voyage abroad, in astronomy, Celsius began a series of observations using colored glass plates to record the magnitude of certain stars. This was the first attempt to measure the intensity of starlight with an other than the human eye. He made observations of eclipses and various objects and published catalogues of carefully determined magnitudes for some 300 stars using his own photometric system. Celsius was the first to perform and publish careful experiments aiming at the definition of a temperature scale on scientific grounds. In his Swedish paper Observations of two persistent degrees on a thermometer he reports on experiments to check that the point is independent of latitude. He determined the dependence of the boiling of water with atmospheric pressure which was even by modern-day standards
8.
Jean-Pierre Christin
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Jean-Pierre Christin was a French physicist, mathematician, astronomer and musician. His proposal to reverse the Celsius thermometer scale was accepted and is still in use today. He was a member of the Académie des sciences, belles-lettres et arts de Lyon. His thermometer was known in France before the Revolution as the thermometer of Lyon, one of these thermometers was kept at Science Museum in London. Mémoire sur lobservation dune éclipse de lune du 18 décembre, et sur quelques particularités relatives à ce phénomène, instrument propre aux opérations de géométrie pratique et dastronomie. Recherches sur les véritables dimensions du pied de roi et du pied de ville, lettre sur lusage de la jauge de Lyon. Parallèle des diverses méthodes de calcul pour mesurer le cercle, démonstration de divers problèmes de géométrie. Méthode pour tracer une méridienne par les hauteurs du soleil, observations sur les baromètres de différents genres. Fixation de la latitude ou élévation du pôle de Lyon, remarque sur la chaleur naturelle du corps humain, observée par le moyen du thermomètre de Lyon. Sur la chaleur directe du soleil, observée par le même instrument, Sur la chaleur des eaux minérales de Baréges. Expériences sur lincubation artificielle des œufs de poule, par le moyen de certains degrés de chaleur, expériences sur les aimants naturels et artificiels de diverses grandeurs. Joseph Jean Baptiste Xavier Fournet, Sur linvention du thermomètre centigrade à mercure, françois Casati, Le Thermomètre de Lyon. Lyon, Editions lyonnaises dart et dhistoire,1992, Académie de Sciencies, Belles-Lettres et Arts de Lyon
9.
Carlos Linneo
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Carl Linnaeus, also known after his ennoblement as Carl von Linné, was a Swedish botanist, physician, and zoologist, who formalised the modern system of naming organisms called binomial nomenclature. He is known by the father of modern taxonomy. Many of his writings were in Latin, and his name is rendered in Latin as Carolus Linnæus, Linnaeus was born in the countryside of Småland, in southern Sweden. He received most of his education at Uppsala University. He lived abroad between 1735 and 1738, where he studied and also published a first edition of his Systema Naturae in the Netherlands and he then returned to Sweden, where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on journeys through Sweden to find and classify plants. In the 1750s and 1760s, he continued to collect and classify animals, plants, and minerals, at the time of his death, he was one of the most acclaimed scientists in Europe. The philosopher Jean-Jacques Rousseau sent him the message, Tell him I know no man on earth. The German writer Johann Wolfgang von Goethe wrote, With the exception of Shakespeare and Spinoza, Swedish author August Strindberg wrote, Linnaeus was in reality a poet who happened to become a naturalist. Among other compliments, Linnaeus has been called Princeps botanicorum, The Pliny of the North and he is also considered as one of the founders of modern ecology. In botany, the abbreviation used to indicate Linnaeus as the authority for species names is L. In older publications, sometimes the abbreviation Linn. is found, Linnæus was born in the village of Råshult in Småland, Sweden, on 23 May 1707. He was the first child of Nicolaus Ingemarsson and Christina Brodersonia and his siblings were Anna Maria Linnæa, Sofia Juliana Linnæa, Samuel Linnæus, and Emerentia Linnæa. One of a line of peasants and priests, Nils was an amateur botanist, a Lutheran minister. Christina was the daughter of the rector of Stenbrohult, Samuel Brodersonius, a year after Linnæus birth, his grandfather Samuel Brodersonius died, and his father Nils became the rector of Stenbrohult. The family moved into the rectory from the curates house, even in his early years, Linnæus seemed to have a liking for plants, flowers in particular. Whenever he was upset, he was given a flower, which calmed him. Nils spent much time in his garden and often showed flowers to Linnaeus, soon Linnæus was given his own patch of earth where he could grow plants
10.
Grado Fahrenheit
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Fahrenheit is a temperature scale based on one proposed in 1724 by the physicist Daniel Gabriel Fahrenheit, after whom the scale is named. It uses the degree Fahrenheit as the unit, several accounts of how he originally defined his scale exist. The lower defining point,0 °F, was established as the temperature of a solution of brine made from parts of ice. Further limits were established as the point of ice and his best estimate of the average human body temperature. All other countries in the world now use the Celsius scale, defined since 1954 by absolute zero being −273.15 °C, on the Fahrenheit scale, the freezing point of water is 32 degrees Fahrenheit and the boiling point is 212 °F. This puts the boiling and freezing points of water exactly 180 degrees apart, therefore, a degree on the Fahrenheit scale is 1⁄180 of the interval between the freezing point and the boiling point. On the Celsius scale, the freezing and boiling points of water are 100 degrees apart, a temperature interval of 1 °F is equal to an interval of 5⁄9 degrees Celsius. The Fahrenheit and Celsius scales intersect at −40°, absolute zero is −273.15 °C or −459.67 °F. For an exact conversion, the formulas can be applied. Again, f is the value in Fahrenheit and c the value in Celsius, f °Fahrenheit to c °Celsius, C °Celsius to f °Fahrenheit, −40 = f. Fahrenheit proposed his temperature scale in 1724, basing it on two points of temperature. In his initial scale, the point is determined by placing the thermometer in a mixture of ice, water. This is a mixture which stabilizes its temperature automatically, that stable temperature was defined as 0 °F. The second point,96 degrees, was approximately the human bodys temperature, in any case, the definition of the Fahrenheit scale has changed since. According to a letter Fahrenheit wrote to his friend Herman Boerhaave, his scale was built on the work of Ole Rømer, whom he had met earlier. In Rømers scale, brine freezes at zero, water freezes and melts at 7.5 degrees, body temperature is 22.5, Fahrenheit multiplied each value by four in order to eliminate fractions and increase the granularity of the scale. Fahrenheit observed that water boils at about 212 degrees using this scale, under this system, the Fahrenheit scale is redefined slightly so that the freezing point of water is exactly 32 °F, and the boiling point is exactly 212 °F or 180 degrees higher. It is for this reason that human body temperature is approximately 98° on the revised scale
