"Thermal inductance Thermal inductance refers to the phenomenon wherein a thermal change of an object surrounded by a fluid will induce a change in convection currents within that fluid, thus inducing a change in the kinetic energy of the fluid. It is considered the thermal analogue to electrical inductance in system equivalence modeling; its unit is the ""thermal henry"". Thus far, few studies have reported on the inductive phenomenon in the heat-transfer behaviour of a system. In 1946, Bosworth demonstrated that heat flow can have an inductive nature through experiments with a fluidic system. He claimed that the measured transient"
"Siemens (unit) The siemens (symbol: S) is the derived unit of electric conductance, electric susceptance and electric admittance in the International System of Units (SI). Conductance, susceptance, and admittance are the reciprocals of resistance, reactance, and impedance respectively; hence one siemens is redundantly equal to the reciprocal of one ohm, and is also referred to as the ""mho"". The 14th General Conference on Weights and Measures approved the addition of the siemens as a derived unit in 1971. The unit is named after Ernst Werner von Siemens. In English, the same form ""siemens"" is used both for the singular and"
"SI derived unit SI derived units are units of measurement derived from the seven base units specified by the International System of Units (SI). They are either dimensionless or can be expressed as a product of one or more of the base units, possibly scaled by an appropriate power of exponentiation. The SI has special names for 22 of these derived units (for example, hertz, the SI unit of measurement of frequency), but the rest merely reflect their derivation: for example, the square metre (m), the SI derived unit of area; and the kilogram per cubic metre (kg/m or kg"
"to distinguish the symbol ""S"" from the lower-case ""s"" where ""second"" is meant, potentially causing confusion. So, for example, a pentode’s transconductance of 2.2 mS might alternatively be written as or (most common in the 1930s) or 2.2 mA/V. A handwritten ""S"" can also be misread as the frequency space variable ""s"", commonly used in transfer functions. Siemens (unit) The siemens (symbol: S) is the derived unit of electric conductance, electric susceptance and electric admittance in the International System of Units (SI). Conductance, susceptance, and admittance are the reciprocals of resistance, reactance, and impedance respectively; hence one siemens is redundantly"
"Until 1995, the SI classified the radian and the steradian as ""supplementary units"", but this designation was abandoned and the units were grouped as derived units. SI derived unit SI derived units are units of measurement derived from the seven base units specified by the International System of Units (SI). They are either dimensionless or can be expressed as a product of one or more of the base units, possibly scaled by an appropriate power of exponentiation. The SI has special names for 22 of these derived units (for example, hertz, the SI unit of measurement of frequency), but the"
"Conductivity (electrolytic) Conductivity (or specific conductance) of an electrolyte solution is a measure of its ability to conduct electricity. The SI unit of conductivity is siemens per meter (S/m). Conductivity measurements are used routinely in many industrial and environmental applications as a fast, inexpensive and reliable way of measuring the ionic content in a solution. For example, the measurement of product conductivity is a typical way to monitor and continuously trend the performance of water purification systems. In many cases, conductivity is linked directly to the total dissolved solids (T.D.S.). High quality deionized water has a conductivity of about 5.5"
"Admittance In electrical engineering, admittance is a measure of how easily a circuit or device will allow a current to flow. It is defined as the reciprocal of impedance. The SI unit of admittance is the siemens (symbol S); the older, synonymous unit is mho, and its symbol is ℧ (an upside-down uppercase omega Ω). Oliver Heaviside coined the term ""admittance"" in December 1887. Admittance is defined as where Resistance is a measure of the opposition of a circuit to the flow of a steady current, while impedance takes into account not only the resistance but also dynamic effects (known"
"m), the SI derived unit of density. The names of SI derived units, when written in full, are in lowercase. However, the symbols for units named after persons are written with an uppercase initial letter. For example, the symbol for hertz is ""Hz""; but the symbol for metre is ""m"". The International System of Units assigns special names to 22 derived units, which includes two dimensionless derived units, the radian (rad) and the steradian (sr). Some other units such as the hour, litre, tonne, bar and electronvolt are not SI units, but are widely used in conjunction with SI units."
"y – shunt admittance per unit length l – length of line C – capacitance of line Admittance In electrical engineering, admittance is a measure of how easily a circuit or device will allow a current to flow. It is defined as the reciprocal of impedance. The SI unit of admittance is the siemens (symbol S); the older, synonymous unit is mho, and its symbol is ℧ (an upside-down uppercase omega Ω). Oliver Heaviside coined the term ""admittance"" in December 1887. Admittance is defined as where Resistance is a measure of the opposition of a circuit to the flow of"
"Transconductance Transconductance (for transfer conductance), also infrequently called mutual conductance, is the electrical characteristic relating the current through the output of a device to the voltage across the input of a device. Conductance is the reciprocal of resistance. Transadmittance (or transfer admittance) is the AC equivalent of transconductance. Transconductance is very often denoted as a conductance, ""g"", with a subscript, m, for ""mutual"". It is defined as follows: For small signal alternating current, the definition is simpler: The SI unit, the siemens, with the symbol, S; 1 siemens = 1 ampere per volt replaced the old unit of conductance, having"
"into effect on 20 May 2019. Derived units may be defined in terms of base units or other derived units. They are adopted to facilitate measurement of diverse quantities. The SI is intended to be an evolving system; units and prefixes are created and unit definitions are modified through international agreement as the technology of measurement progresses and the precision of measurements improves. The most recent derived unit, the katal, was defined in 1999. The reliability of the SI depends not only on the precise measurement of standards for the base units in terms of various physical constants of nature,"
"International System of Units The International System of Units (SI, abbreviated from the French "") 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, which are the ampere, kelvin, second, metre, kilogram, candela, mole, and 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 also specifies names for 22 derived units, such as lumen and watt, for other common physical quantities."
"Susceptance In electrical engineering, susceptance (""B"") is the imaginary part of admittance, where the real part is conductance. The inverse of admittance is impedance, where the imaginary part is reactance and the real part is resistance. In SI units, susceptance is measured in siemens. Oliver Heaviside first defined this property in June 1887. The general equation defining admittance is given by where, The admittance (formula_2) is the inverse of the impedance (formula_7) or where Note: The susceptance formula_5 is the imaginary part of the admittance formula_2. The magnitude of admittance is given by: Reactance is defined as the imaginary part"
"1 Ω⋅m. Electrical conductivity or specific conductance is the reciprocal of electrical resistivity, and measures a material's ability to conduct an electric current. It is commonly represented by the Greek letter σ (sigma), but κ (kappa) (especially in electrical engineering) or γ (gamma) are also occasionally used. Its SI unit is siemens per metre (S/m). In an ideal case, cross-section and physical composition of the examined material are uniform across the sample, and the electric field and current density are both parallel and constant everywhere. Many resistors and conductors do in fact have a uniform cross section with a uniform"
"the normalised impedance using the lower case ""z"" is given by Similarly, for normalised admittance The SI unit of impedance is the ohm with the symbol of the upper case Greek letter omega (Ω) and the SI unit for admittance is the siemens with the symbol of an upper case letter S. Normalised impedance and normalised admittance are dimensionless. Actual impedances and admittances must be normalised before using them on a Smith chart. Once the result is obtained it may be de-normalised to obtain the actual result. Using transmission line theory, if a transmission line is terminated in an impedance"
"in ohms is numerically equal to the resistivity of the material it is made of in Ω⋅m. Conductivity, σ, is the inverse of resistivity: Conductivity has SI units of ""siemens per metre"" (S/m). For less ideal cases, such as more complicated geometry, or when the current and electric field vary in different parts of the material, it is necessary to use a more general expression in which the resistivity at a particular point is defined as the ratio of the electric field to the density of the current it creates at that point: where in which formula_10 and formula_11 are"
"vowel of the prefixed units kiloohm and megaohm is commonly omitted, producing kilohm and megohm. In alternating current circuits, electrical impedance is also measured in ohms. The siemens (symbol: S) is the SI derived unit of electric conductance and admittance, also known as the mho (ohm spelled backwards, symbol is ℧); it is the reciprocal of resistance in ohms (Ω). The power dissipated by a resistor may be calculated from its resistance, and the voltage or current involved. The formula is a combination of Ohm's Law and Joule's law: where: A linear resistor has a constant resistance value over all"
"power in a given period is equal to zero. Due to its dependence on frequency, magnetic inductance is mainly observable in magnetic circuits which operate at VHF and/or UHF frequencies. The notion of magnetic inductivity is employed in analysis and computation of circuit behavior in the gyrator–capacitor model in a way analogous to inductance in electrical circuits. Magnetic impedance (SI unit: Ω) is the ratio of a sinusoidal magnetic tension formula_11 to a sinusoidal magnetic current formula_12 in a gyrator–capacitor model. Analogous to electrical impedance, magnetic impedance is likewise a complex variable. Magnetic impedance is also called the ""full"" magnetic"
"susceptance materials are used in susceptors built into microwavable food packaging for their ability to convert microwave radiation into heat. Susceptance In electrical engineering, susceptance (""B"") is the imaginary part of admittance, where the real part is conductance. The inverse of admittance is impedance, where the imaginary part is reactance and the real part is resistance. In SI units, susceptance is measured in siemens. Oliver Heaviside first defined this property in June 1887. The general equation defining admittance is given by where, The admittance (formula_2) is the inverse of the impedance (formula_7) or where Note: The susceptance formula_5 is the"
"SI base unit The International System of Units (SI) defines seven units of measure as a basic set from which all other SI units can be derived. The SI base units and their physical quantities are the meter for measurement of length, the kilogram for mass, the second for time, the ampere for electric current, the kelvin for temperature, the candela for luminous intensity, and the mole for amount of substance. The SI base units form a set of mutually independent dimensions as required by dimensional analysis commonly employed in science and technology. The names and symbols of SI base"
"derived quantities can be specified in terms of the SI base and derived units that have no named units in the SI system, such as acceleration, which is defined in SI units as m/s. The SI base units are the building blocks of the system and all the other units are derived from them. When Maxwell first introduced the concept of a coherent system, he identified three quantities that could be used as base units: mass, length and time. Giorgi later identified the need for an electrical base unit, for which the unit of electric current was chosen for SI."
"Inertance Inertance is a measure of the pressure difference in a fluid required to cause a unit change in the rate of change of volumetric flow-rate with time. The base SI units of inertance are kg m or Pa m s and the usual symbol is I. The inertance of a tube is given by: where The pressure difference is related to the change in flow-rate by the equation: where This equation assumes constant density, that the acceleration is uniform, and that the flow is fully developed ""plug flow"". This precludes sharp bends, water hammer, and so on. To some,"
"Statmho The statmho is the unit of electrical conductance in the electrostatic system of units (ESU), an extension of the centimeter-gram-second (CGS) system to cover electrical units. In the ESU system, the permittivity of free space is set to unity by definition. This results in unit conversions to the SI system containing a power of the speed of light, ""c"", as well as a power of 10. In the case of the statmho, the conversion from siemens (S) is given by: 1 S ≡ 10""c"" statmho The value of ""c"" in the SI system is 299,792,458 metres per second exactly"
"SI unit of power is the watt, which is numerically equivalent to the var. A sinusoidally alternating voltage applied to a purely resistive load results in an alternating current that is fully in phase with the voltage. However, in many applications it is common for there to be a reactive component to the system, that is, the system possesses capacitance, inductance, or both. These electrical properties cause the current to change phase with respect to the voltage: capacitance tending the current to lead the voltage in phase, and inductance to lag it. For sinusoid currents and voltages at the same"
"used with SI prefixes. The most commonly used derived unit is the millilitre, defined as one-thousandth of a litre, and also often referred to by the SI derived unit name ""cubic centimetre"". It is a commonly used measure, especially in medicine, cooking and automotive engineering. Other units may be found in the table below, where the more often used terms are in bold. However, some authorities advise against some of them; for example, in the United States, NIST advocates using the millilitre or litre instead of the centilitre. One litre is slightly more than one US liquid quart and slightly"
"the modern revision of the metric system. It is the world's most widely used system of units, both in everyday commerce and in science. The SI was developed in 1960 from the metre-kilogram-second (MKS) system, rather than the centimetre-gram-second (CGS) system, which, in turn, had many variants. During its development the SI also introduced several newly named units that were previously not a part of the metric system. The original SI units for the seven basic physical quantities were: The mole was subsequently added to this list and the degree Kelvin renamed the kelvin. There are two types of SI"
"Degas conductivity, where conductivity is measured after dissolved carbon dioxide has been removed from the sample, either through reboiling or dynamic degassing. Conductivity detectors are commonly used with ion chromatography. Conductivity (electrolytic) Conductivity (or specific conductance) of an electrolyte solution is a measure of its ability to conduct electricity. The SI unit of conductivity is siemens per meter (S/m). Conductivity measurements are used routinely in many industrial and environmental applications as a fast, inexpensive and reliable way of measuring the ionic content in a solution. For example, the measurement of product conductivity is a typical way to monitor and continuously"
"(). Its symbol is usually , and it may be represented by writing its magnitude and phase in the form . However, cartesian complex number representation is often more powerful for circuit analysis purposes. The reciprocal of impedance is admittance, whose SI unit is the siemens, formerly called mho. The term ""impedance"" was coined by Oliver Heaviside in July 1886. Arthur Kennelly was the first to represent impedance with complex numbers in 1893. In addition to resistance as seen in DC circuits, impedance in AC circuits includes the effects of the induction of voltages in conductors by the magnetic fields"
"referenced to the values of the fundamental constants, namely the Planck constant (""h""), the electron charge (""e""), the Boltzmann constant (""k""), and the Avogadro constant (""N""). This approach was approved in 2018, only after measurements of these constants were achieved with sufficient accuracy. SI base unit The International System of Units (SI) defines seven units of measure as a basic set from which all other SI units can be derived. The SI base units and their physical quantities are the meter for measurement of length, the kilogram for mass, the second for time, the ampere for electric current, the kelvin"
"μS/m at 25 °C, typical drinking water in the range of 5–50 mS/m, while sea water about 5 S/m (or 50,000 μS/cm) (i.e., sea water's conductivity is one million times higher than that of deionized water:). Conductivity is traditionally determined by connecting the electrolyte in a Wheatstone bridge. Dilute solutions follow Kohlrausch's Laws of concentration dependence and additivity of ionic contributions. Lars Onsager gave a theoretical explanation of Kohlrausch's law by extending Debye–Hückel theory. The SI unit of conductivity is S/m and, unless otherwise qualified, it refers to 25 °C. Often encountered in industry is the traditional unit of μS/cm."
"various derived quantities like formula_3, the inductive coupling factor and formula_4, the inductive leakage factor. formula_3 is derived according to : where Other transformer parameters like leakage inductance and mutual inductance which cannot be directly measured may be defined in terms of k. Short-circuit inductance is one of the parameters that determines the resonance frequency of the magnetic phase synchronous coupling in a resonant transformer and wireless power transfer. Short-circuit inductance is the main component of the current-limiting parameter in leakage transformer applications. Short-circuit inductance Short-circuit inductance of a real linear two-winding transformer is inductance measured across the primary or"
"unsuitable for precision measurements of a property of a body, and this makes a unit of weight unsuitable as a base unit. The derived units in the SI are formed by powers, products or quotients of the base units and are unlimited in number. Derived units are associated with derived quantities; for example, velocity is a quantity that is derived from the base quantities of time and length, and thus the SI derived unit is metre per second (symbol m/s). The dimensions of derived units can be expressed in terms of the dimensions of the base units. Combinations of base"
"of the geometry of the design (e.g. area of the plates and the distance between them) and the permittivity of the dielectric material between the plates of the capacitor. For many dielectric materials, the permittivity and thus the capacitance, is independent of the potential difference between the conductors and the total charge on them. The SI unit of capacitance is the farad (symbol: F), named after the English physicist Michael Faraday. A 1 farad capacitor, when charged with 1 coulomb of electrical charge, has a potential difference of 1 volt between its plates. The reciprocal of capacitance is called elastance."