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Ebulliometer
In physics, an ebulliometer () is an instrument designed to accurately measure the boiling point of liquids by measuring the temperature of the vapor–liquid equilibrium either isobarically (at constant pressure) or isothermally (at constant temperature). The primary components in a Świętosławski ebulliometer, which operates isobarically, are the boiler, the Cottrell pumps, the thermowell, and the condenser. Such an ebulliometer can be used for extremely accurate measurements of boiling temperature, molecular weights, mutual solubilities, and solvent purities by using a resistance thermometer (RTD) to measure the near-equilibrium conditions of the thermowell. The ebulliometer is frequently used for measuring the alcohol content of dry wines. See also Sweetness of wine and Oechsle scale The Oechsle scale is a hydrometer scale measuring the density of grape must, which is an indication of grape ripeness and sugar content used in wine-making. It is named for Ferdinand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boiling Point
The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor. The boiling point of a liquid varies depending upon the surrounding environmental pressure. A liquid in a partial vacuum, i.e., under a lower pressure, has a lower boiling point than when that liquid is at atmospheric pressure. Because of this, water boils at 100°C (or with scientific precision: ) under standard pressure at sea level, but at at altitude. For a given pressure, different liquids will boiling, boil at different temperatures. The normal boiling point (also called the atmospheric boiling point or the atmospheric pressure boiling point) of a liquid is the special case in which the vapor pressure of the liquid equals the defined atmospheric pressure at sea level, one Atmosphere (unit), atmosphere. At that temperature, the vapor pressure of the liquid becomes sufficient to overcome atmospheric pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wojciech Świętosławski
Wojciech Alojzy Świętosławski (Polish pronunciation: ; 1881–1968) was a Polish physical chemist, who is considered the "father of modern thermochemistry". He developed a static method of cryometric measurement and a new method of testing coal. Świętosławski was vice-chairman of the International Union of Pure and Applied Chemistry (IUPAC) and created the foundations for a new branch of physical chemistry: polyazeotropy. In 1933 he became a member of the Temporary Advisory and Scientific Committee. Early years Świętosławski was born on 21 June 1881 in the village of Kiryjówka, Volhynia Governorate, Russian Empire. He spent his early years in Kiev, where he graduated from high school (1899). In 1906, he graduated with an engineering degree at Chemistry Department of Kiev Technical University. His first research paper, "Thermochemical Analysis of Organic Compounds" was published in 1908, in "Polish Yearly Magazine ("Rocznik Polski"). In appreciation of his work, Św ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physics
Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events." It is one of the most fundamental scientific disciplines. "Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of physics. (...) You will come to see physics as a towering achievement of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boiling
Boiling or ebullition is the rapid phase transition from liquid to gas or vapor, vapour; the reverse of boiling is condensation. Boiling occurs when a liquid is heated to its boiling point, so that the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the Standard atmosphere (unit), surrounding atmosphere. Boiling and evaporation are the two main forms of liquid vapourization. There are two main types of boiling: nucleate boiling, where small bubbles of vapour form at discrete points; and critical heat flux boiling, where the boiling surface is heated above a certain critical temperature and a film of vapour forms on the surface. Transition boiling is an intermediate, unstable form of boiling with elements of both types. The boiling point of water is 100 °C or 212 °F but is lower with the decreased atmospheric pressure found at higher altitudes. Boiling water is used as a method of making it potable by killing Microorganism, microbes an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Measuring Instrument
Instrumentation is a collective term for measuring instruments, used for indicating, measuring, and recording physical quantities. It is also a field of study about the art and science about making measurement instruments, involving the related areas of metrology, automation, and control theory. The term has its origins in the art and science of scientific instrument-making. Instrumentation can refer to devices as simple as direct-reading thermometers, or as complex as multi- sensor components of industrial control systems. Instruments can be found in laboratories, refineries, factories and vehicles, as well as in everyday household use (e.g., smoke detectors and thermostats). Measurement parameters Instrumentation is used to measure many parameters (physical values), including: *Pressure, either differential or static * Flow *Temperature * Levels of liquids, etc. *Moisture or humidity *Density *Viscosity * ionising radiation * Frequency * Current *Voltage * Induct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isobarically
In thermodynamics, an isobaric process is a type of thermodynamic process in which the pressure of the system stays constant: Δ''P'' = 0. The heat transferred to the system does work, but also changes the internal energy (''U'') of the system. This article uses the physics sign convention for work, where positive work is work done by the system. Using this convention, by the first law of thermodynamics, : Q = \Delta U + W\, where ''W'' is work, ''U'' is internal energy, and ''Q'' is heat. Pressure-volume work by the closed system is defined as: :W = \int \! p \,dV \, where Δ means change over the whole process, whereas ''d'' denotes a differential. Since pressure is constant, this means that : W = p \Delta V\, . Applying the ideal gas law, this becomes : W = n\,R\,\Delta T with ''R'' representing the gas constant, and ''n'' representing the amount of substance, which is assumed to remain constant (e.g., there is no phase transition during a chemical react ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isothermally
An isothermal process is a type of thermodynamic process in which the temperature ''T'' of a system remains constant: Δ''T'' = 0. This typically occurs when a system is in contact with an outside thermal reservoir, and a change in the system occurs slowly enough to allow the system to be continuously adjusted to the temperature of the reservoir through heat exchange (see quasi-equilibrium). In contrast, an ''adiabatic process'' is where a system exchanges no heat with its surroundings (''Q'' = 0). Simply, we can say that in an isothermal process * T = \text * \Delta T = 0 * dT = 0 * For ideal gases only, internal energy \Delta U = 0 while in adiabatic processes: * Q = 0. Etymology The noun '' isotherm'' is derived from the Ancient Greek words (), meaning "equal", and (), meaning "heat". Examples Isothermal processes can occur in any kind of system that has some means of regulating the temperature, including highly structured machines, and even living cells. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frederick Gardner Cottrell
Frederick Gardner Cottrell (January 10, 1877 – November 16, 1948) was an American physical chemist, inventor and philanthropist. He is best known for his invention of the electrostatic precipitator, one of the first inventions designed to eliminate air pollution—and for establishing the Research Corporation for Science Advancement, a foundation that has funded scientific research since 1912. Biography He was born on January 10, 1877, in Oakland, California, to Cynthia (née Durfee) and Henry Cottrell, both prominent families going back to the settlement of America. Cottrell's immense curiosity gained him notice early in life. One acquaintance said, “He read textbooks like novels.” He finished high school at age 16, entered the University of California, Berkeley, and graduated in 3 years. After graduation, he taught chemistry at Oakland High School, saving money (his annual salary was $1,200) until he could afford to continue his formal education. A notation in hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermowell
Thermowells are cylindrical fittings used to protect temperature sensors installed to monitor industrial processes. A thermowell consists of a tube closed at one end and mounted on the wall of the piping or vessel within which the fluid of interest flows. A temperature sensor, such as a thermometer, thermocouple, or resistance temperature detector, is inserted in the open end of the tube, which is usually in the open air outside the piping or vessel and any thermal insulation. Thermodynamically, the process fluid transfers heat to the thermowell wall, which in turn transfers heat to the sensor. Since more mass is present with a sensor-well assembly than with a probe directly immersed into the fluid, the sensor's response to changes in temperature is slowed by the addition of the well. If the sensor fails, it can be easily replaced without draining the vessel or piping. Since the mass of the thermowell must be heated to the fluid temperature, and since the walls of the thermowe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Condenser (heat Transfer)
In systems involving heat transfer, a condenser is a heat exchanger used to Condensation, condense a gaseous substance into a liquid state through cooling. In doing so, the latent heat is released by the substance and transferred to the surrounding environment. Condensers are used for efficient heat rejection in many industrial systems. Condensers can be made according to numerous designs and come in many sizes ranging from rather small (hand-held) to very large (industrial-scale units used in plant processes). For example, a refrigerator uses a condenser to get rid of heat extracted from the interior of the unit to the outside air. Condensers are used in air conditioning, industrial chemical processes such as distillation, steam power plants, and other heat-exchange systems. The use of cooling water or surrounding air as the coolant is common in many condensers. History The earliest laboratory condenser, a "Heat exchanger, Gegenstromkühler" (counter-flow condenser), was inven ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resistance Thermometer
Resistance thermometers, also called resistance temperature detectors (RTDs), are sensors used to measure temperature. Many RTD elements consist of a length of fine wire wrapped around a heat-resistant ceramic or glass core but other constructions are also used. The RTD wire is a pure material, typically platinum (Pt), nickel (Ni), or copper (Cu). The material has an accurate resistance/temperature relationship which is used to provide an indication of temperature. As RTD elements are fragile, they are often housed in protective probes. RTDs, which have higher accuracy and repeatability, are slowly replacing thermocouples in industrial applications below 600 °Celsius, C. Resistance/temperature relationship of metals Common RTD sensing elements for biomedical application constructed of platinum (Pt), nickel (Ni), or copper (Cu) have a repeatability, repeatable, resistance versus temperature relationship (''R'' vs ''T'') and operating temperature range. The ''R'' vs ''T'' re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
