The discussion revolves around the measurement of extremely low resistance, specifically below one nano-ohm, in the context of superconductors. Participants explore various measurement techniques and devices, as well as the implications of superconductivity at room temperature.
Participants do not reach a consensus on the existence of room temperature superconductors, with some asserting they do not exist yet, while others imply the possibility of having developed one. The discussion includes multiple viewpoints on measurement techniques and challenges without resolving disagreements.
Participants highlight the technical challenges associated with measuring low resistance, including the need for specific measurement setups and the influence of geometry on current density and voltage drop. There is also uncertainty regarding the practicality of using certain measurement devices.
This discussion may be of interest to those involved in experimental physics, materials science, and electrical engineering, particularly in the context of superconductivity and low-resistance measurement techniques.
That's one nano-ohm, which could be tough to measure!Jlarkin84 said:What device can I use to measure resistance lower than .000000001?
Have a look at this recent thread (click the little up-arrow in the title bar of the quote to be taken to that thread):Jlarkin84 said:I have a question. What device can I use to measure resistance lower than .000000001? Conductor is 6 inches by 1/4 thick. I had to make it big due to equipment limitations
auto_v said:TL;DR Summary: Testing superconductor
Hi, I would like someone to test the superconductor I have come up with or let me know how ( I don't have a lab ), what I can say that the resistance is almost zero with my Fluke.Regards
Another way would be to place the sample in a solenoid inductor. The inductance will fall when the sample becomes superconducting, as it will exclude the magnetic field from that part of the solenoid. Changes in inductance can be measured very accurately.marcusl said:Superconductors expel magnetic fields, so one way to tell if you have a superconductor is to place it in a uniform magnetic field, cool it through the transition temperature, and watch the external fields change.
marcusl said:You may not be aware that there are no room temperature superconductors—yet. Superconductors expel magnetic fields, so one way to tell if you have a superconductor is to place it in a uniform magnetic field, cool it through the transition temperature, and watch the external fields change.
Thank yall!. I looked up the cost of the equipment for nanoohms and that ain't happening. To rich for my blood. I did buy a milliohm meter and it can't determine resistance either. So I read one of those threads and gonna do what yall suggested them, take it to a lab. Safran is gonna help me out. They have that nanoohm device and experience to use it. Ty!!Jlarkin84 said:I have a question. What device can I use to measure resistance lower than .000000001? Conductor is 6 inches by 1/4 thick. I had to make it big due to equipment limitations
Not actual measurement, but kind of a cheap comparison which works just fine for bigger plates/pieces:Jlarkin84 said:Conductor is 6 inches by 1/4 thick.
I've seen that problem with TO-3 transistor cases. We had to paint them sometimes.Baluncore said:Or would you simply be measuring your body temperature in the mirror?