Talk:Electrical conductivity

Table of SI units
I noticed that the table of SI electromagnetism units was on several entries, so I think I'll make an entry just for it and then put a link to it at the bottom of the entries that it used to be in. — Preceding unsigned comment added by TDogg310 (talk • contribs) 22:17, 31 July 2005 (UTC)

Measuring Electrical Conductivity in Fluids
Measuring the conductivity of a metal rod is relatively simple, but how do you measure the conductivity of a fluid? Will a horizontal glas tube with facing(inert)platimum disk-electrodes at each end (so you can calculate the length and area of the fluid column do the trick? One can then apply a AC voltage accross the electrodes and measure the current to calculate the resistance of the fluid column and hence calculate the conductivity of the fluid.

What is the recommended practice?--168.209.98.35 20:24, 9 December 2005 (UTC)G Francois Marais

Electric conductivity measuring instruments for liquids are commercially available from laboratory equipment suppliers. After calibrating the instrument the probe containing the measuring cell is simply immersed in the liquid for a digital readout of the conductivity and the temperature (conductivity varies with temperature).--168.209.98.35 15:41, 14 December 2005 (UTC)G Francois Marais

Electrical expreiments with potatoes
I seem to remember in high school science, something about potatoes being used as conductors or like a primative battery. Am I wrong?209.74.5.35


 * You can use a potato as a battery. This should be disussed under battery, if it isn't already. --Heron 15:30, 25 March 2006 (UTC)

Table of conductivity and resistivity
I propose that we combine the tables of conductivity and resistivity onto their own page, because they are fundamentally related. Comments? Fresheneesz 22:44, 27 May 2006 (UTC)


 * Agreed. — Omegatron 19:02, 24 February 2007 (UTC)

Electrical Conductivity: Gas
I have something on my mind that I want to clarify. Is there a gas that can conduct an electrical charge were it will move within that specific gas only/mostly? - Johan1984
 * Lightning - Rip-Saw 10:43, 21 August 2007 (UTC)

Temperature Dependance
The formula seems not quite right. It causes most conductivity to increase with temperature instead of being reduced. As far as I can tell the T and the Tprime are out of order. 63.164.202.130 14:35, 30 August 2007 (UTC)63.164.202.130 14:33, 30 August 2007 (UTC)rfilabs
 * This is because the formula is for semiconductors, where electrical conductivity increases with increasing temperature. The formula is for calibrating an EC water meter using a calibration solution. Different EC meters use different slopes. This section probably needs a bit of tidying and sectioning to specify the EC dependence for metals and semiconductors (such as water). + m t  01:09, 28 May 2008 (UTC)

the text says the conductivity is directly proportional to temperature, whereas it's inversely proportional.--132.65.16.64 (talk) 19:09, 28 June 2010 (UTC)
 * Please read the text - directly for semiconductors, inversely for metals. Materialscientist (talk) 22:47, 28 June 2010 (UTC)

Even with Semiconductors it is not very common to have the electrical conductivity directly proportional to temperature. More typical is an exponential dependence. So this part is not absolutely wrong, but its prone to misinterpretation and not really useful. So I would better remove it. The more important point is that for many (non magnetic) pure metals a resistivity proportional to absolute temperature is a reasonable approximation for not so limited range of temperature. --Ulrich67 (talk) 20:34, 23 December 2010 (UTC)

Current Density or Free Current Density
I suppose there's an imprecision on the definition of the electrical conductivity:

"The conductivity σ is defined as the ratio of the current density J to the electric field strength E"

I believe it must say: ...the ratio fo the FREE current density etc..

since the total current density depends on the free and the bounded current (see Magnetization).

--Felipebm (talk) 16:00, 7 May 2008 (UTC)

conductivity

This page is really helpful.

Thanks

Kingpenguins —Preceding unsigned comment added by Kingpenguins2007 (talk • contribs) 23:21, 24 February 2009 (UTC)

What a HORRIBLE entry. Not a single mention of the electron!! Gross negligence.69.40.254.72 (talk) 14:40, 6 November 2010 (UTC)

Superconductivity
Maybe mention it somewhere in the text (general properties) and link to its article. Or just in the related links. —Preceding unsigned comment added by 161.53.198.136 (talk) 23:30, 9 September 2009 (UTC)

High Voltage Power Distribution
Added text about Aluminium being commonly used for High Voltage Power Distribution ie. between electricity "Transmission" Towers. Mostly due to lighter weight, and cost(?) for same current carrying capacity. Wondering if this has always been the case? Aluminium is not cheap, (Copper more expensive?) Aluminium ironically need HEAPS of Electricity to refine. A bit off-topic, but? --220.101.28.25 (talk) 23:16, 3 December 2009 (UTC)
 * Going to aluminium and copper and -F for "price" brings a picture that copper is some 2.5 times more expensive than Al. I've heard Al is reinforced with steel core for power lines. Materialscientist (talk) 23:22, 3 December 2009 (UTC)

Classification of electrical conduction
Electrical conductivity is potential to facilitate flow of charge (Q). There are currently two ways charge can be conducted in an electric field setup: Please note this. — Preceding unsigned comment added by Otivaeey (talk • contribs) 14:26, 13 December 2010 (UTC)
 * free-electron flow theory (in solid and plasma)
 * ion-carrier (in liquid only, such as the mechanism of hydronium ion migration/relay)