home made SMD tweezers for LCR meter?

[SArepairman]

Is there anything special about SMD tweezers for a LCR meter?

I can buy a de-5000 meter for 90$ or I can buy a de-5000 meter with accessories (alligator clips and SMD tweezers) for 140$. I can see how SMD tweezers might be slightly useful... but what is special about them? Can I just take normal tweezers and glue some 16 gauge silicone wire to them and put some kind of sharp contact at the end?

If that wire going to the end of the tweezers is shielded can I just throw a braid shield over it?

I have some plastic tweezers, wire, shield braid, banana jacks, copper tape...... do you think I can make a home made solution to match the factory tweezers and alligator clip attachments?
http://www.ebay.com/itm/DER-EE-DE-5000-Handheld-LCR-Multi-Meter-TL-21-TL-22-TL-23-Air-Mail-Free-Shipping-/181284166220?pt=LH_DefaultDomain_0&hash=item2a3560da4c

By using three pieces of shield braid I could cover the tweezers up to the point of the contact, slipping one over the wire leading to the meter (twisted i guess) and one over each side of the tweezers, then I could put some heat shrink tubing over it to make it look nice...

Again, I have all the materials I need on hand, is there any traps to look out for here? The only thing I am not sure about is what to make the electrical contacts out of.

[notsob]

Dave has done a review on the de-5000, you should have a look at it.

[peter.mitchell]

Yes and no.
Some are special, others are not.

Some are designed in such a way that their inductance and capacitance does not change with usage, eg if wires twist, inductance will stay the same. Others are designed with this in mind AND a kelvin connection, right at the tip of the tweezers. Some are characterized to be flat across a typical meters measurement frequency range.

On the other hand, some are as you have said, just tweezers with wire on them.

[SArepairman]

any idea how the de-5000 tweezers are?

i guess im just looking to beat or meet those. i guess i cant worry about a kelvin connection because the de5000 only has two ports.

[apelly]

The de-5000 has 4 wire terminals. As notsob suggested, watch Dave's review. There are also a couple of good threads here that are pretty easy to find.

I bought one a while ago. If you have any more questions I'll do my best to answer them, although I know there are a few more capable people than me on the forum who also have one.

[TMM]

any idea how the de-5000 tweezers are?

i guess im just looking to beat or meet those. i guess i cant worry about a kelvin connection because the de5000 only has two ports.

The plug/module on the DE5000 tweezers and alligator clips uses a double sided PCB that goes into the component slots to achieve a 4 wire connection. The banana jacks aren't used.

The DE5000 tweezers are worth the money if you are buying a DE5000 anyway. Trying to DIY something would be far more effort than it is worth and probably no where near as robust. My only complaint about the tweezers is that they could do with sharper points as the tips are a bit clumsy for anything less than 1206. Shouldn't be hard to fix as the metal tips are just held in with screws.

[robrenz]

The DE-5000 tweezers are 4 wire kelvin to within 1-1/2" from the tip. You could do better than that with home made but It probably would not change the accuracy much since you would do a open/closed calibration with the tweezers anyway. The DE-5000 does have Split banana jacks that carry the 4 wire connection but good luck on finding matching split plugs and keeping the splits in the right orientation.  I have the Fluke 2x4 kelvin probes that match the split jacks on the 884XA bench meters but the splits are the wrong orientation to work on the DE-5000.

FWIW 3 videos I did on making kelvin connections
kelvin pinchers
kelvin probes
kelvin banana jacks

[dr.diesel]

kelvin pinchers
kelvin probes
kelvin banana jacks

Everytime I watch one of your videos I feel inadequate!  Awesome work, you are truly gifted,   .

[robrenz]

Thanks, I hope they encourage people to make things.  I agree they are gifts given by the creator, I can't take much credit.

[SArepairman]

Ah fair enough I will buy the tweezers then, there is no point on trying to save a dime they are pretty elaborate.

Out of curiosity are the tweezers shielded?

hopefully in a month I will join the LCR club.

[robrenz]

They are shielded just up to the tweezer body then it is a pcb with 2 traces up to where the tips connect.

[SArepairman]

They are shielded just up to the tweezer body then it is a pcb with 2 traces up to where the tips connect.

ah, i just watched the video now and I am watching your videos, that seems like a useful thing to make.

[jaxbird]

FWIW 3 videos I did on making kelvin connections
kelvin pinchers
kelvin probes
kelvin banana jacks

Beautiful work , but a bit beyond the average home made attempts I'd say

Joining the sense and current wires within a reasonably short distance (1/2 inch or 10mm) from the measurement point will be just fine for even low value measurements.

[robrenz]

Joining the sense and current wires within a reasonably short distance (1/2 inch or 10mm) from the measurement point will be just fine for even low value measurements.

Thanks, glad you enjoyed them.

If you have a microOhmeter that gives stable single digit µOhm readings, you can easily see that 1/2" difference in connections. Current and sense locations at these levels is critical.

[jaxbird]

Thanks, glad you enjoyed them.

If you have a microOhmeter that gives stable single digit µOhm readings, you can easily see that 1/2" difference in connections. Current and sense locations at these levels is critical.

In low values I was thinking the more practical low milliohms and mid µohms .. Low µohms and beyond is indeed very tricky with so many factors suddenly becoming very significant.

[GreyWoolfe]

Robrenz, I bow, get on my knees and knock my head 3 times on the floor .  You have tremendous talent.  The way you so casually do things and easily explain them is a mark of a true craftsman.  I applaud you.

[robrenz]

Robrenz, .... I applaud you.

Thanks, I am glad you enjoyed them.  As you can tell from the number of views these are not everybody's cup of tea.

[SeanB]

I do enjoy those Robrenz. You are a very good machinist.

[robrenz]

Thanks SeanB,  That means a lot coming from you with your obviously vast experience in just about everything

[SeanB]

I just know a little about some things, not going to claim to any great knowledge of everything. I do terribly at Trivial pursuit unless the right questions come up. Same with quizzing. Do not even go to sporting.....

[dreamcat4]

Have ordered today a DE-5000 without the TL-22 tweezers... they do not seem to be in stock anywhere. So getting the official ones seems not an option.

But perhaps this cheap pair can be modified?

https://www.aliexpress.com/item/32960851599.html

...will have to watch those videos from @robrenz youtube channel and learn. The meter does already come with the TL-21 short clips. So perhaps that existing box can be re-used. However at the expense of giving that up, or requiring to purchase another TL-21... just to make it all nicely fitting onto the contacts and sturdy durable etc.

 

[dreamcat4]

huh... it seems there are other existing and available smd tweezers for uni-t LCR meter

TH26029C

https://www.aliexpress.com/item/4001268000597.html
https://www.aliexpress.com/item/1005004002581902.html
https://www.aliexpress.com/item/1005001914614650.html

TH26009C

https://www.aliexpress.com/item/1005003618158452.html
https://www.aliexpress.com/item/1005002531915200.html
https://www.aliexpress.com/item/1005003546707018.html




so perhaps those could be made work with some extra persuasion... might be possible... maybe...

[dreamcat4]

heres another couple of options

https://www.ebay.co.uk/itm/324313324468