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This seems like a silly question, but my research is failing to yield results...

I ordered some new probes for my multimeter because I needed things like alligator clip leads and the little wire clips instead of just the pointy spikes.

enter image description here

Problem is they don't fit. Well, ok, they do "fit" (I can insert the plug in the hole) but the contacts don't touch, rendering them useless. Looking at other sets of probes, they all seem to have this sheathed attachment, and none have the simple banana plug that the default probes came with.

  • Is this multimeter just too low end to fit standard probes?
  • Are there multiple multimeter probe plug standards?
  • What is this plug called so I know what to search for? (ones a "banana" plug, right? What's the other?)
  • Are there adapters I can buy?

enter image description here enter image description here

Success! enter image description here

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  • \$\begingroup\$ Do the new leads seat fully in the hole; i.e. is that cut-away of the insulating sleeve required? I'm not sure, but I'd guess the full sleeve is required to meet some specific CAT level. \$\endgroup\$ – Nick T Jan 10 '15 at 21:54
  • \$\begingroup\$ I think the sleeves are too long, so when fully inserted no contact is made. I think shorter sleeves would be fine. I think. \$\endgroup\$ – Alex Wayne Jan 10 '15 at 21:56
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    \$\begingroup\$ Can you fully insert them though? I'd call it "fully inserted" if the right-angle part is touching (or only slightly above) the multimeter body. \$\endgroup\$ – Nick T Jan 10 '15 at 21:58
  • \$\begingroup\$ I see what you mean now... No, there is about a half inch between the multimeter and the bottom of the right angle plug. \$\endgroup\$ – Alex Wayne Jan 10 '15 at 22:01
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    \$\begingroup\$ The plastic tip on the longer-sleeved probe is a safety feature to prevent any incidental contact with the contact (can't jam your fingers in there). If you shorten the sleeve, it's kind of pointless, but it should still just be a banana jack where it counts. \$\endgroup\$ – Nick T Jan 10 '15 at 22:37
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It's to meet safety standards that require the "male" part to be insulated so you won't shock yourself if you touch the probe and it's not plugged in.

It's possible (advisable or not is another question) to modify the probes with an X-Acto knife or box cutter so they will fit your multimeter.

enter image description here

The ideal solution is to replace your multimeter with a new one that supports the safer probes, at least from the pov of the regulations and the manufacturers of multimeters.

Edit: Re your added photos, check to make sure the inside is the same and the only thing keeping it from mating is the sheath. Here is the inside of the ones I have modified for an older Uni-T multimeter (used only for low voltage < 30V):

enter image description here

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  • \$\begingroup\$ It just depends on what you're going to measure. If all that's dealt with is sub-30 volts, it's fine. I wouldn't stick those probes in a wall socket though. \$\endgroup\$ – Nick T Jan 10 '15 at 21:56
  • \$\begingroup\$ @NickT On the plus side, if cut correctly, they'll be no more (or less) dangerous than the previous ones. For mains measurements I use a Fluke with the big cartridge fuse (only). \$\endgroup\$ – Spehro Pefhany Jan 10 '15 at 21:57
  • \$\begingroup\$ Yeah this is all for microntroller style stuff. I plan on rarely going as high 12V. So this may be the solution. \$\endgroup\$ – Alex Wayne Jan 10 '15 at 22:05
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    \$\begingroup\$ Added a photo of the cut sheath above. Thanks! Works perfect! But I'll try to keep it to low voltage with this set to be safe :) \$\endgroup\$ – Alex Wayne Jan 10 '15 at 22:48
  • \$\begingroup\$ I wouldn't use an anonymous multimeter like that on high voltages anyway. \$\endgroup\$ – markrages Jan 11 '15 at 0:13
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It sounds like you bought fairly cheap probes. Not to worry, it's a simple fix (if I understand what you're describing right).

The problem sounds like the internal metal pin is too thin to connect with the socket. If you look down the end of the connector you'll see the pin, and it should be formed out of 4 individual segments in a cross shape:

enter image description here

All you need to do is spread those segments apart a little. Just insert a small screwdriver into the slots and twist a little to spread them.

enter image description here

You should then find it's a bit stiffer to insert the plug into the socket and the probes now work.

And none of that compromises the safety.

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I had EXACTLY same problem recently. Turns out, the cylindrical contact inside cheap plugs was very slightly off-center, so it bumped into the side of the socket tube and prevented the plug from being inserted fully.

Using pliers I managed to squeeze its top part enough to fit in. However after using it for couple days I gave up and bought a new set of leads. Only twice as expensive but fit perfectly, 50cm longer and much more flexible silicone.

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I had exactly the same problem. I thought it was only me being unlucky. My leads came with the meter. I tries to open up the plug a little but it snapped off. As i wont be using very high voltages or currents i bought 4mm banana plugs and connected them to the lead

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