The ampere balance (also current balance or Kelvin balance) is an electromechanical apparatus used for the precise measurement of the SI unit of electric current, the ampere. It was invented by William Thomson, 1st Baron Kelvin.
The current to be measured is passed in series through two coils of wire, one of which is attached to one arm of a sensitive balance. The magnetic force between the two coils is measured by the amount of weight needed on the other arm of the balance to keep it in equilibrium. This is used to calculate the numerical value of the current.
The main weakness of the ampere balance is that the calculation of the current involves the dimensions of the coils. So the accuracy of the current measurement is limited by the accuracy with which the coils can be measured, and their mechanical rigidity.
A more complicated version of an ampere balance, that removes this source of inaccuracy by a calibration step, is the Kibble balance, invented by Bryan Kibble in 1975. This experimental device was developed at government metrology laboratories worldwide with the goal of providing a more accurate definition of the kilogram, the world's standard of mass. In this application, the Kibble balance functions in the reverse sense to the Ampere balance: it was used to weigh the International Prototype of the Kilogram, defining the kilogram in terms of an electric current and a voltage. In 2019, the kilogram, ampere, kelvin, and mole were redefined in terms of fundamental constants, removing the dependence on physical objects.
Determining the Permeability of Free Space Through an Ampere Balance ...
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Ampere Balance | Help with Physics Homework
Ampere Balance | Help with Physics Homework
Ampere Balance | Help with Physics Homework
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Principle of ampere-second balance | Download Scientific Diagram
Principle of ampere-second balance | Download Scientific Diagram
The ampere balance (also current balance or Kelvin balance) is an electromechanical apparatus used for the precise measurement of the SI unit of electric current, the ampere. It was invented …
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Ampere balance – measurement of μ o This apparatus can be used to determine the value of μ o ,the permeability of free space. The apparatus used is known as an ampere balance and one …
The Kibble balance is a more accurate version of the ampere balance, an early current measuring instrument in which the force between two current-carrying coils of wire is measured and then …
It describes in detail the radically modified fixed and moving coils of the current balance; the measurements made on the coil dimensions; computa-tions of their fields and interactions; …
The ampere balance (also current balance or Kelvin balance) is an electromechanical apparatus used for the precise measurement of the SI unit of electric current, the ampere. It was invented …
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Mar 12, 2018 · When loading the transformer the secondary will produce an mmf that is balanced by the primary mmf with a small deviation in terms of magnetization current on the primary. …
The ampere balance (also current balance or Kelvin balance) is an electromechanical apparatus used for the precise measurement of the SI unit of electric current, the ampere. It was invented …
