Robin M220 Miliohmeter?

[ColinTheAmpMan1]

Duncan,
Could you possibly post a photograph of both ends of the leads in the same picture? Your photo of the meter shows four connections but the photo of the leads doesn't show both ends. I have a Vici VC480C milliohm meter and the leads look a bit similar; they have two leads going to each "big crocodile clip".
Colin.

[Granitehill]

You can get Kelvin clips and leads ready to go for less than £10 on the usual auction site.

I've got a Rhopoint M210, which is a small digital milliohmeter. It's a REALLY useful bit of test gear - great for chasing bad switch contacts, making up meter shunts, etc etc. Mine is in near-constant use.
Rhopoint sell replacement kelvin leads, but they are about £60 a pair !

[duncanlowe]

Originally Posted by ColinTheAmpMan1

Duncan,
Could you possibly post a photograph of both ends of the leads in the same picture? Your photo of the meter shows four connections but the photo of the leads doesn't show both ends. I have a Vici VC480C milliohm meter and the leads look a bit similar; they have two leads going to each "big crocodile clip".
Colin.

Both ends are the same. There are two leads. Each lead has two wires, a red and a black. both ends are terminated the same with two 4mm shrouded test plugs. I'll look at taking a photo later.

The unit came with two insulated croc clips, but they have only one 4mm hole. I suspect there should be some two hole Kelvin croc clips that are missing.

On a positive note, I've unstuck the meter. There was no sign of the debris I was expecting, but the coil was too close to the magnet at one end with plenty of clearance at the other. So I tweaked the pivots slightly to make the coil sit more centrally around the magnet, and now nice and free. Rebuilt it and I gor nice meter operation and was able to zero. However before I could do more everything just stopped. Even the little red LED that had always worked until now was out. I gave up in disgust (temporarily) at that point and will go back to it later. I hope it's simply muck on the battery terminals.

[duncanlowe]

So. It appears to work. One day I will learn to solder (or more precisely not rush the final solder joint).

If I switch on, I can set zero. Connecting all four wires to a fairly substantial piec of metal, the zero stays, as you'd expect. If I press the 'test' with the 2 ohm range selected it reads around 1 ohm.

So I need to get some low ohm reference resistors to check it out.

Another couple of observations. On one of the PCBs is some writing. It looks very much like a German or French hand. Could this be a rebrand of something else? Also the leather case is unusual. On the one hand seems hand made, but if so it's certainly not home made. Proper stitching and rivet / press studs. Also an unidentified strap inside to hold something else that is missing.

I've added a photo of one lead, the other is the same. I'll be buying some proper clips now I know it actually functions. Also a couple of photos of the insides.

[duncanlowe]

Just a quick update. Purchased a couple of sets of Kelvin probes. One set with leads, other set to fit the existing leads. Well the set for the existing leads it turns out don't actually have 4mm holes so will be drilled out to size eventually. The other set had safety sheathing on the 4mms. So as purchased nothing fits. But with the safety sheath removed (these won't be used on anything live) one set fits, and I can confirm that a couple of test resistances (500R, 0.02R) read almost perfectly.

So my only open question is, how come I can't find any information, anywhere about this meter? Is it really that rare? Given the oddball case is it a prototype that got out? I suspect its more likely just an instrument that went obsolete very quickly, but it will keep me happy reading low ohms.

[Phil G4SPZ]

Robin were apparently bought by Fluke. There is some info here: https://www.kewtechcorp.com/about-us/heritage

It’s a great pity that manufacturers often pay scant regard to their legacies and history. I guess that Fluke simply dispensed with all Robin web-based data, and why not? The Robin brand was defunct.

I have experienced a similar situation when trying to research other test gear manufacturers such as Comark, Nombrex, Record and Advance. The only remaining information seems to be that posted by amateur enthusiasts. The fact that so much information still survives is pure Fluke (...sorry!)