DIY 4wire probes/Kelvin clamps

[MosherIV]

Hi, so I bought these cheap clamp probes ages ago (Aug2016) and have only just got round to wiring them up. For anyone who wants to know the tricks to making them.

I got them from Amazon :
https://www.amazon.co.uk/gp/product/B00XOL4332/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1
I got the cheapest ones I cound find on Amazon, yes I know I can get them cheaper on ebay, banggood etc but I prefer the protection and customer service from Amazon.

They come with no instructions, so you have to figure out what to do yourself.
First, take them apart by removing the spring.
Then lift and slide out each prong.

Solder a wire to each prong :


Be careful not to let solder overflow down the side of the prong, they fit tight in the plastic shell and solder will stop them fitting.

[MosherIV]

Next insert one prong into the shell :



Feed the wire through the hole in the shell :



I added a cable tie for strain releif

Do the same on the other side.

[MosherIV]

Now the really trick part - putting the spring back in!



Sorry, I did not take any pictures of putting the spring back in but I needed both hands and them some to do it 

Make sure the short side of the spring is on the insulated probe (the insulation stops the spring acting as a short between both prongs)
I found the easiest technique to be pushing the spring in until the long spring rests on the wire.
Then use something like a screw driver to lift the short spring (do not let it drag on the insulation on the prong - it will drag and lift it  ). Use screw driver as a slide for the spring, use your finger and push the centre of the spring and the short arm will just slide along the screw driver blade.
When the spring loop is in line with the shell pivot, it is on place. Carefully lift and slide the screw driver out.


(Sorry - forgot to take a picture of the black one at this point)

[MosherIV]

Finally, I used some heat shrink to hold the wires together and make it look neat :


I used them on my Schlumberger 7155Plus which has 4wire resistance measurement :



This is it measuring a 0.1
Had to null out the probes to get an accurate masurement on this low a reading