Editing Wheatstone bridge (section)

== Significance ==
The Wheatstone bridge illustrates the concept of a difference measurement, which can be extremely accurate. Variations on the Wheatstone bridge can  be used to measure [[capacitance]], [[inductance]], [[Electrical impedance|impedance]] and other quantities, such as the amount of combustible gases in a sample, with an [[explosimeter]].  The [[Kelvin bridge]] was specially adapted from the Wheatstone bridge for measuring very low resistances.  In many cases, the significance of measuring the unknown resistance is related to measuring the impact of some [[physical phenomenon]] (such as force, temperature, pressure, etc.) which thereby allows the use of Wheatstone bridge in measuring those elements indirectly.

The concept was extended to [[alternating current]] measurements by [[James Clerk Maxwell]] in 1865<ref>{{cite journal |last1=Maxwell |first1=J. Clerk |title=A dynamical theory of the electromagnetic field |journal=Philosophical Transactions of the Royal Society of London |date=1865 |volume=155 |pages=459–512 |bibcode=1865RSPT..155..459M |url=https://archive.org/details/dynamicaltheoryo00maxw/page/458/mode/2up}}  Maxwell's bridge used a battery and a [[ballistic galvanometer]].  See pp. 475–477.</ref> and further improved as {{vanchor|Blumlein bridge}} by [[Alan Blumlein]] in British Patent no. 323,037, 1928.