查看“︁韦斯顿电池”︁的源代码

{{Unreferenced|time=2024-06-05T13:03:47+00:00}}
'''韦斯顿电池'''是一种[[原电池]]，1893年由[[英国]]化学家[[爱德华·韦斯顿 (化学家)|爱德华·韦斯顿]]（Edward Weston）发明。由于其高度稳定的[[电动势]]，多用于实验室中[[电位计]]的校准。1911年该电池被采纳为电动势的国际标准。

韦斯顿电池的[[负极]]是[[镉]][[汞齐]]，[[正极]]是液态[[汞]]以及糊状[[硫酸亚汞]]（Hg<sub>2</sub>SO<sub>4</sub>），电解质溶液使用[[硫酸镉]]（CdSO{{sub|4}}）溶液。

电池表达式为
Cd(5%~12%)(Hg)<sub>x</sub>|CdSO<sub>4</sub>·<math>\frac{8}{3}H_2O(s)</math>|CdSO<sub>4</sub>(sat)|CdSO<sub>4</sub>·<math>\frac{8}{3}H_2O(s)</math>|Hg<sub>2</sub>SO<sub>4</sub>(s)|Hg(l)

放电时发生如下反应：

:Cd + Hg<sub>2</sub>SO<sub>4</sub> = CdSO<sub>4</sub> + 2Hg

在20℃时其电动势为1.01865[[伏特|V]]。

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[[Image:Westoncell.jpg|right]]

The '''Weston cell''', invented by [[Edward Weston (chemist)|Edward Weston]] in 1893, is a [[wet cell|wet-chemical cell]] that produces a highly stable [[voltage]] suitable as a laboratory standard for [[calibration]] of [[voltmeter]]s. It was adopted as the International Standard for [[electromotive force|EMF]] in 1911.

==Chemistry==

The [[anode]] is an [[amalgam]] of [[cadmium]] with [[mercury (element)|mercury]]，the [[cathode]] is of pure mercury, the [[electrolyte]] is a [[solution]] of [[cadmium sulfate]] and the [[depolarizer]] is a paste of [[mercurous sulfate]]。

As shown in the illustration, the cell is set up in an H-shaped glass vessel with the cadmium amalgam in one leg and the pure mercury in the other.  Electrical connections to the cadmium amalgam and the mercury are made by [[platinum]] wires fused through the lower ends of the legs.

==Characteristics==

The original design was a saturated cadmium cell producing a convenient 1.0183 [[Volt]] reference and had the advantage of having a lower [[temperature coefficient]] than the previously used [[Clark cell]].  (Reference cells must be applied in such a way that no current is drawn from them.)

The temperature coefficient can be reduced by shifting to an unsaturated design, the predominant type today.  However, an unsaturated cell's output decreases by some 80 microvolts per year, which is compensated by periodical calibration against a saturated cell.

==Patent==
* {{US patent|494827}}, "''Voltaic cell''"

==参见==

* [[Primary cell terminology]]

==Sources==

* ''Practical Electricity'' by W. E. Ayrton and T. Mather, published by Cassell and Company, London, 1911, pp 198-203

==外部链接==
*[http://humboldt.edu/~scimus/Instruments/Elec-Duff/StdCellDuff.htm Standard Cells]
*[http://www.allaboutcircuits.com/vol_1/chpt_11/4.html Special-purpose batteries]
[[Category:Electric batteries]]
[[Category:Electrochemistry]]


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==外部链接==
*[https://web.archive.org/web/20090207053925/http://humboldt.edu/~scimus/Instruments/Elec-Duff/StdCellDuff.htm 標準電池] {{En}}
*[http://www.allaboutcircuits.com/vol_1/chpt_11/4.html 專用電池] {{Wayback|url=http://www.allaboutcircuits.com/vol_1/chpt_11/4.html |date=20150506084100 }} {{En}}

{{電池}}

[[Category:电化学]]
[[Category:电池]]
[[Category:電池類型]]