Timeline for Can you measure different currents at different contact points for a volume of material made of two different metals with different conductivities?
Current License: CC BY-SA 4.0
10 events
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| Apr 26, 2023 at 8:02 | comment | added | jackw2556 | @FlatterMann Thanks again for your help-really appreciated! I'll see what I can find in the literature | |
| Apr 25, 2023 at 12:58 | comment | added | FlatterMann | Conductivity in metals is hard to measure reliably because the total resistance of the sample is usually much smaller than that of the wiring and the contacts between the test sample and the probes. There is a lot of literature (both in physics and engineering) that describes experimental techniques that removes errors that are due to both wiring and contact resistance (like the four terminal method). You will still need a precise Voltmeter with mV or higher resolution if you want to make precise measurements on bulk metals and you may have to correct for sample geometry. | |
| Apr 25, 2023 at 9:26 | comment | added | jackw2556 | @JonCuster Thanks Jon! That was my initial thought as well. I think I managed to confuse myself when looking into it further. | |
| Apr 25, 2023 at 9:24 | comment | added | jackw2556 | @FlatterMann Thanks for your help! We are considering the possibilities with mapping conductivity in a long metal components as part of our research. At the moment its just trying to understand the nature of what ideas could be viable. When you say in practice it would be useless, I can imagine that could be due to being unable to measure sufficient resolution or high possibility for errors, or do you mean in resolving what the current measurements actually mean in terms of conductivity, or something else? Thank you for the reading suggestions as well-I'll look into them! | |
| S Apr 24, 2023 at 18:57 | history | suggested | ZaellixA | CC BY-SA 4.0 |
Converted all equations and symbols to MathJax
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| Apr 24, 2023 at 15:42 | comment | added | Jon Custer | Clearly in the limit that one conductivity or the other goes to zero the ammeters will not read the same... | |
| Apr 24, 2023 at 15:39 | comment | added | FlatterMann | No need to apologize. Would you mind telling us where this came from? It's a very poor method to measure conductivities and in practice more or less useless. While the two circuit diagrams are equivalent (the voltage source was simply moved between the two current loops), it misrepresents what would actually happen in such a setup once we include actual wire and contact resistance. A much better method goes back to Thomson and Kelvin (and there are improvements over this, too): en.wikipedia.org/wiki/Four-terminal_sensing | |
| Apr 24, 2023 at 15:24 | review | Suggested edits | |||
| S Apr 24, 2023 at 18:57 | |||||
| S Apr 24, 2023 at 15:06 | review | First questions | |||
| Apr 24, 2023 at 15:24 | |||||
| S Apr 24, 2023 at 15:06 | history | asked | jackw2556 | CC BY-SA 4.0 |