Author Topic: Decent kelvin clip leads?  (Read 15837 times)

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Offline dadlerTopic starter

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Decent kelvin clip leads?
« on: March 20, 2015, 11:13:56 pm »
Anyone have any suggestions on decent quality Kelvin clip leads? Intended for use with my new Agisight bench DMM.

Asks:
  • prefer small-ish
  • prefer sub $150 for the pair
  • dual shrouded 4mm banana plugs on each clip lead

I really like the DIY clips made by robrenz here: https://www.eevblog.com/forum/projects/video-of-making-the-ultimate-kelvin-connection-(major-hacking-of-a-pomona-clip)/

But I don't think I could pull that off. If someone sold these, I would be all over the mini grabber version.

* I found these on Mouser, but I have never heard of SilverTronic and they are huge:

http://www.mouser.com/Search/ProductDetail.aspx?R=129141virtualkey55150000virtualkey835-129141

* This set from Probemaster seems ok (and I have found Probemaster to be decent, not excellent, quality), but they are also huge:

http://www.probemaster.com/product_info.php?cPath=2_15&products_id=195

I prefer smaller clips. I am also content with supplying the lead DIY style if someone can offer a source on high quality clips alone?

Thanks in advance for any responses.
 

Offline ManateeMafia

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Re: Decent kelvin clip leads?
« Reply #1 on: March 21, 2015, 12:35:29 am »
How about a Pomona 6283-C cable cut in half and terminated with Mueller BU-75K clips? The Pomona is made with RG-58 cable. It might be a little to bulky for the test clips.


http://www.mouser.com/Search/Refine.aspx?Keyword=bu-75k

http://www.mouser.com/Search/Refine.aspx?Keyword=6283-c





 

Offline ManateeMafia

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Re: Decent kelvin clip leads?
« Reply #2 on: March 21, 2015, 12:50:25 am »
Looking again at the cable, it is probably not the best choice since the force and sense are on opposite cables. My bad.

 The clips are still a good choice. I have some and the only complaint is that they don't always stay on the component leads. If they had deeper grooves they would hold better.
 

Offline McBryce

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Re: Decent kelvin clip leads?
« Reply #3 on: March 21, 2015, 09:56:44 am »
I bought these for my Keithley 2000: http://www.ebay.de/itm/261267737565

Despite their very low price, they are relatively good quality and tick all the boxes for my needs. They are also quite short (about 60cm), which was on my wishlist too. The only complaint I could have is that they claim to be CAT III when they most certainly aren't. Mine didn't have the heatshrink on them as shown in the picture (not that that would have made them CAT III anyway), but that doesn't bother me as I only intend using them for 4-wire resistance measurements and low-voltage stuff.

McBryce.
30 Years making cars more difficult to repair.
 

Offline dadlerTopic starter

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Re: Decent kelvin clip leads?
« Reply #4 on: March 21, 2015, 08:13:36 pm »
I bought these for my Keithley 2000: http://www.ebay.de/itm/261267737565

Despite their very low price, they are relatively good quality and tick all the boxes for my needs. They are also quite short (about 60cm), which was on my wishlist too. The only complaint I could have is that they claim to be CAT III when they most certainly aren't. Mine didn't have the heatshrink on them as shown in the picture (not that that would have made them CAT III anyway), but that doesn't bother me as I only intend using them for 4-wire resistance measurements and low-voltage stuff.

McBryce.

At thanks for the link! those look decent and pretty compatible with my needs--just low voltage 4-wire resistance measurement. I might try out a set.
 

Offline dadlerTopic starter

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Re: Decent kelvin clip leads?
« Reply #5 on: March 21, 2015, 08:15:28 pm »
How about a Pomona 6283-C cable cut in half and terminated with Mueller BU-75K clips? The Pomona is made with RG-58 cable. It might be a little to bulky for the test clips.


http://www.mouser.com/Search/Refine.aspx?Keyword=bu-75k

http://www.mouser.com/Search/Refine.aspx?Keyword=6283-c

Ah thanks for these links. I found the Mueller clips before, but they looked huge. I've never seen this brand of clips in person. I realize now they are only 1.6" long, which is small-ish.
 

Offline LaurenceW

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Re: Decent kelvin clip leads?
« Reply #6 on: March 22, 2015, 07:51:57 pm »
I've recently bought some REALLY CR@P CHEAP costing (and looking) Kelvin clips of Ebay. Whoever assembled them DIDN'T HAVE A CLUE WHAT THEY WERE DOING, which only became clear when the probes arrived.

The normal trick for Kelvin "aligator-type" clips is to have each side of the jaw of each clip separated, electrically, so that they only contact one another VIA the lead of the component under test, so ensuring true four wire V and I contact. The probes I bought only had one jaw wired! The same design fault was evident on both connectors. I am convinced this was a design fault, and not a one-off manufacturing fault.

Anyway, I learned, not for the first/last time, that cheap cr@p off ebay is always just that.
If you don't measure, you don't get.
 

Offline SeanB

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Re: Decent kelvin clip leads?
« Reply #7 on: March 22, 2015, 07:56:29 pm »
Look at forum member ROBRENZ for DIY versions.

https://www.youtube.com/user/ROBRENZ/videos

Here is his version of DIY Kelvin clips.



 

Offline dadlerTopic starter

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Re: Decent kelvin clip leads?
« Reply #8 on: March 23, 2015, 12:18:30 am »
Look at forum member ROBRENZ for DIY versions.

https://www.youtube.com/user/ROBRENZ/videos

Here is his version of DIY Kelvin clips.



Thanks. I actually mentioned these in my first post, just don't think I could pull off this level of DIY. He has really nice tools.
 

Offline McBryce

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Re: Decent kelvin clip leads?
« Reply #9 on: March 23, 2015, 09:32:54 am »
I can upload close-up pictures of the €20 kelvin clips I bought on ebay (http://www.ebay.de/itm/261267737565) if anyone wants to take a closer look. The wires definitely go to opposite sides of the clips :D

McBryce.
30 Years making cars more difficult to repair.
 

Offline dadlerTopic starter

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Re: Decent kelvin clip leads?
« Reply #10 on: March 23, 2015, 07:45:45 pm »
I can upload close-up pictures of the €20 kelvin clips I bought on ebay (http://www.ebay.de/itm/261267737565) if anyone wants to take a closer look. The wires definitely go to opposite sides of the clips :D

McBryce.

I would appreciate that If you wouldn't mind!

I am tempted to order a set of these, although I am a bit concerned about the longevity of the interesting elastic spring mechanism: http://www.ebay.com/itm/400486938037
 

Offline DanielS

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Re: Decent kelvin clip leads?
« Reply #11 on: March 23, 2015, 08:16:32 pm »
Look at forum member ROBRENZ for DIY versions.

https://www.youtube.com/user/ROBRENZ/videos

Here is his version of DIY Kelvin clips.



Thanks. I actually mentioned these in my first post, just don't think I could pull off this level of DIY. He has really nice tools.
Those do look pretty neat. The construction is far more complex than it could have been though: if he could manufacture a die set (or two for rough-cut + finish), he could simply stamp the replacement leads out of sheet metal. That would scale much better beyond a small one-off batch.

It always makes me smile to see a DIYer beats established manufacturers at their own game.
 

Offline McBryce

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Re: Decent kelvin clip leads?
« Reply #12 on: March 23, 2015, 09:11:47 pm »
Here's some close-ups. The connector is protected (caps are included). The clip plastic is pretty well dimensioned. It feels very solid in the hand and I'd say they will last quite a while. The only complaint I might have is that the core of the banana connector isn't solid, it's a folded steel type. But these can easily be swapped. They're no hi-end product, but you get what you pay for.

McBryce.

30 Years making cars more difficult to repair.
 

Offline rosbuitre

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Re: Decent kelvin clip leads?
« Reply #13 on: March 31, 2015, 11:01:57 am »
Hi
Anyone have these Extech 380465 Test Lead Set?
Will be compatible with my Keysight 34461A?

Regards



Update, TestEquity  response

Hello Osvaldo,
They are not compatible.

Best Regards
TestEquity
« Last Edit: March 31, 2015, 05:08:45 pm by rosbuitre »
My instruments: DMM Keysight 34461A / Tektronix DMM916 / Fluke 12, Rigol DS1074Z, Deer DE-5000, Siglent SDG805 / SDP3303D, Dayton Dats2
 

Offline dadlerTopic starter

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Re: Decent kelvin clip leads?
« Reply #14 on: April 02, 2015, 08:49:05 pm »
Hi
Anyone have these Extech 380465 Test Lead Set?
Will be compatible with my Keysight 34461A?

Regards



Update, TestEquity  response

Hello Osvaldo,
They are not compatible.

Best Regards
TestEquity

How could they not be compatible?

http://www.amazon.com/Extech-380465-Kelvin-Milliohm-Models/dp/B004WN5HEK

They look perfectly compatible with any DMM using 4 separate banana jacks for current/voltage sense.

I almost ordered a set until I saw your updated post. Maybe they mean not "officially compatible" or something-or they have some bizarre proprietary connector (?).

Anyways I did order a set of the eBay Kelvin clips (with the translucent rubber band 'springs') that I linked above. Will report on quality when I receive them.
« Last Edit: April 02, 2015, 09:00:30 pm by dadler »
 

Offline rosbuitre

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Re: Decent kelvin clip leads?
« Reply #15 on: April 02, 2015, 10:48:54 pm »
Hi
Anyone have these Extech 380465 Test Lead Set?
Will be compatible with my Keysight 34461A?

Regards



Update, TestEquity  response

Hello Osvaldo,
They are not compatible.

Best Regards
TestEquity

How could they not be compatible?

http://www.amazon.com/Extech-380465-Kelvin-Milliohm-Models/dp/B004WN5HEK

They look perfectly compatible with any DMM using 4 separate banana jacks for current/voltage sense.

I almost ordered a set until I saw your updated post. Maybe they mean not "officially compatible" or something-or they have some bizarre proprietary connector (?).

Anyways I did order a set of the eBay Kelvin clips (with the translucent rubber band 'springs') that I linked above. Will report on quality when I receive them.

Maybe they mean not "officially compatible" or something-or they have some bizarre proprietary connector (?).

That must be the reason, should change the banana connectors

Regards
My instruments: DMM Keysight 34461A / Tektronix DMM916 / Fluke 12, Rigol DS1074Z, Deer DE-5000, Siglent SDG805 / SDP3303D, Dayton Dats2
 

Offline bson

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Re: Decent kelvin clip leads?
« Reply #16 on: April 03, 2015, 04:47:19 am »
I can upload close-up pictures of the €20 kelvin clips I bought on ebay (http://www.ebay.de/itm/261267737565) if anyone wants to take a closer look. The wires definitely go to opposite sides of the clips :D
They can also be found on ebay.com... http://www.ebay.com/itm/261267733426
I just ordered a set.
 

Offline rosbuitre

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Re: Decent kelvin clip leads?
« Reply #17 on: April 11, 2015, 01:19:51 pm »
I can upload close-up pictures of the €20 kelvin clips I bought on ebay (http://www.ebay.de/itm/261267737565) if anyone wants to take a closer look. The wires definitely go to opposite sides of the clips :D
They can also be found on ebay.com... http://www.ebay.com/itm/261267733426
I just ordered a set.

Hi
The received ?, are they good?

Regards
My instruments: DMM Keysight 34461A / Tektronix DMM916 / Fluke 12, Rigol DS1074Z, Deer DE-5000, Siglent SDG805 / SDP3303D, Dayton Dats2
 

Offline bson

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Re: Decent kelvin clip leads?
« Reply #18 on: April 14, 2015, 06:44:51 am »
They can also be found on ebay.com... http://www.ebay.com/itm/261267733426
I just ordered a set.
Hi
The received ?, are they good?

Regards
Just received them today.   They work great, especially for low resistances.  On my 34465A after a bit of warmup and a thermal calibration and nulling, a Dale .1ohm .1% 5W resistor reads 000.1004 ohm on 4W.  The same probes, nulled, on 2W read 000.0988 ohm.  Looks good to me!

By comparison my handheld LCR meter (calibrated and nulled) reads 0.087ohm and my various handheld DMMs are so off I'd frankly rate them as useless for such a small value.

So, yeah, mechanically okay - good grip, good lead contact, good plugs, good maws, practical test lead length, soft and pliable, first impression is they're probably going to work fine.  Not much of an opinion on durability yet of course.

A bit light and plasticy, not Flukely/Tek/Keysight, no rubberized grips or anything else fancy.  But they seem to do the job...
« Last Edit: April 14, 2015, 06:48:21 am by bson »
 

Offline McBryce

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Re: Decent kelvin clip leads?
« Reply #19 on: April 14, 2015, 12:55:24 pm »
Regarding durability, I've had mine quite a while now and I've had no problems with them breaking/bending/falling apart. For €20 they're an absolute bargain, at least for the measurements I need to do.
As bson said, "They're not Fluke / Tek / Keysight" but then again, neither is the price.

McBryce.
30 Years making cars more difficult to repair.
 

Offline rosbuitre

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Re: Decent kelvin clip leads?
« Reply #20 on: April 14, 2015, 11:46:18 pm »
Hi
Thanks for the info  :-+

Regards
My instruments: DMM Keysight 34461A / Tektronix DMM916 / Fluke 12, Rigol DS1074Z, Deer DE-5000, Siglent SDG805 / SDP3303D, Dayton Dats2
 

Offline eas

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Re: Decent kelvin clip leads?
« Reply #21 on: April 27, 2015, 04:47:49 am »
I can upload close-up pictures of the €20 kelvin clips I bought on ebay (http://www.ebay.de/itm/261267737565) if anyone wants to take a closer look. The wires definitely go to opposite sides of the clips :D

McBryce.

I would appreciate that If you wouldn't mind!

I am tempted to order a set of these, although I am a bit concerned about the longevity of the interesting elastic spring mechanism: http://www.ebay.com/itm/400486938037

For what it is worth, those "springs" look like short lengths of silicone lab tubing.
 

Offline dadlerTopic starter

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Re: Decent kelvin clip leads?
« Reply #22 on: April 27, 2015, 05:17:45 am »
I did end up ordering a set of the "elastic band" Kelvin leads and they actually work rather well. The spring force could be a tad higher, but certainly usable and good quality. I guess silicone tubing will make a good replacement if the originals wear out  :-+
 

Offline JBaughb

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Offline dadlerTopic starter

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