Ok, this is getting really interesting indeed!!
While waiting for Amazon to deliver we decided to use the Hioki IM3536 with the kludge fixture above, 1m cables included. These cables are just 2 wire with shield cable we had, and have the wires to 2 BNCs and shield to BNC shell. The wires are not heavy just small #22~24 or so.
After some thinking about the Short calibration and attempting to remove the effects of DUT contact area, the method we were using was to use a Zero ohm 2512 SMD as the Zero Ohm DUT, however we have no means to "know" how close this SMD is to 0, and thus just "assumed" it to be 0.
Also remember we are using a split contact concept with the fixture to help deal with the SMD end terminations, and the Force and Sense lines are not brought together by the fixture, the idea is the DUT end terminations make the Force Sense connections on each end of the DUT. This helps reduce the effects of contact to the SMD device by making the DUT perform the Kelvin connection.
Back the unknown Zero ohm SMD, we decided to use a quality 1 milliohm 1% 2512 as the Zero Ohm DUT and do a short Cal with this "knowing" it's 0.001 ohms. Then we just add 0.001 ohms to the readings, or just RTFM and use the reference and scale functions, no time for the manual now tho.
So does this work? You bet, stunningly good we might add, absolutely superb repeatability in the milliohm regions!! Here's some additional 2512 1% low valued resistors measured with the Hioki IM3536, set to Rdc, 16 average, 0.1 ohm range. Repeatability is excellent too!!
Value (milliohms) Reading (milliohms) Added for DMM6500 (milliohms)
10 10.04 10.026
15 14.97 14.868
20 20.06 20.016
40 39.90 39.916
50 50.03 50.065
100 100.25 100.242
Later we'll shorten the leads, as they a much too long at over a meter, and maybe spend so time RTFM
BTW this doesn't require a heavy scaled ultra low impedance fixture with massive terminals and wires, just some simple thin cable, few BNCs and a kludge PCB with a $1 Lever Arm used for holding flat items, a 2512 resistor is a flat item...so why not?? Well, we must thank Sir Lord Kelvin again
Anyway, if you have a quality lab grade LCR meter, might want to give this Lever Arm with Split Contact SMD Fixture a try, doesn't cost much and it just works
We tried to measure these low ohm resistors with the nice Tonghui $200 tweezers, repeatability is hopeless below ~0.1 ohm.
Best,
Edit: added DMM6500 readings above, had to go from center point BNC to single banana on all 4 BNC centers and no ground connections. Another kludge setup but giving good repeatable results!!