Following on from a post from @SimosMCmuffin link I developed a very simple excel calculator sheet to check purity of nickel strip by calculating its resistivity - inputs are physical dimensions of strip ( length x width x thickness) and volt drop for a given current. The excel sheet then calculates resistivity ( ohm per cubic metre) and also back calculates what the resistance should be for both pure nickel and carbon steel ( the usual fake nickel strip) .
I used this to check some nickel strip I had (10mm wide by 0.15mm thick) and cut a 300mm length , soldered on some wires and connected it to my 5A CCCV charger set to 5A .
The volt drop across the 30mm length of strip was 80mV and the resistivity back calculated to 8.0 E-08 compared to 100% nickel resistivity of 7.0 E-08- so conclusion was its the good stuff Attached is a picture of my results
Don’t seem to be able to attach excel files to here but I can sent it to anyone - or if anyone knows how to attach excel files - let me know