Resistance Calculation of a Probe/Sockets
The contact resistance of a spring contact probe/Sockets assembly is critical to successful testing. Listed below for reference are calculations of the approximate resistance.
Plunger Valuation
1mm diameter rod, 17.78mm long Beryllium Copper base material, Gold over nickel plating 1.24 mΩ
Barrel Valuation
25.4mm long pillar, 1.07mm inside diameter, 1.36mm outside diameter, hard gold material and plating 8.32 mΩ
Spring Valuation
0.15mm wire diameter, 190.5mm in length Music Wire base material, Gold over nickel plating 2125.09 mΩ
Sockets Valuation;
30.48mm long , 1.38mm inside diameter, 1.68mm outside diameter, Nickel/silver base material, Gold over nickel plating 13.20 mΩ The values;
listed above are Valuations. However, they are sufficient for the intended purpose. When determining the current path of the probe, it is
important;to note that current in parallel paths will divide itself between the paths such that the products of current and resistance in each path
are equal for all paths.