Dear Colleagues,
I have some brittle samples in the form of PELLET.
I want to measure resistivity and some other properties by four probe method.
How to confirm the proper electric connection of the leads with the sample ?
Is there any theory regarding the distance of the probes from the sample surface ?
Please discuss .
Thanks in advance
N Das
Dear Nityananda Das
One of the important ingredients for making and keeping a reliable electrical connection is clean contact surfaces. The other important ingredient—force—was covered in “The Trouble with Torque in Electrical Connections.
This sounds logical because if the high contact force is decreased, the contact resistance remains constant and does not increase until a much lower force is reached. See Fig. 1. This would be expected with welding, not with a spring-like mechanism. For cold welding to occur, clean surfaces and massive distortion are required. This is accomplished by proper contact preparation, abrasion from relative motion, and volume reduction during the high forces.
Hope this helps.
Regards
Silver plated(gold the best)contacts along with spring pressure with clean smooth surface are advisable for better contacts....
- Badges
- Science topic
- Similar topics
- Biological Science
- Bioecology
- Systems Ecology
- Landscape Ecology
- Connectivity