EEVblog Electronics Community Forum

Products => Test Equipment => Topic started by: Giallograle on November 07, 2024, 06:50:32 am

Title: Kelvin clips
Post by: Giallograle on November 07, 2024, 06:50:32 am
I need some Kelvin clips for a used Agilent 34401A multimeter, through hole and tweezers for SMD.

I'd like decent quality, and as I'm in Asia, I'll be looking on Taobao. Are there any good-value brands to look out for?

Thanks!
Title: Re: Kelvin clips
Post by: squadchannel on November 07, 2024, 06:54:48 am
ETA ETA3108
not bad for the price. :-+
https://en.tw-eta.com/index.php?c=category&id=22
Title: Re: Kelvin clips
Post by: Giallograle on November 07, 2024, 11:32:17 am
Good value, but unshielded?

Have I missed something?
Title: Re: Kelvin clips
Post by: HighVoltage on November 07, 2024, 12:00:41 pm
Good value, but unshielded?

Have I missed something?

What are shielded kelvin clips?
Title: Re: Kelvin clips
Post by: coromonadalix on November 07, 2024, 12:42:11 pm
the 5th wire,  some  are coax shielded and all 4 probes shield are connected together (5th) to a ground body of the instrument

as for efficiency ???

Title: Re: Kelvin clips
Post by: squadchannel on November 07, 2024, 12:49:56 pm
I don't know what you mean by shield kenvin clips, but usually coax cable shields are used with a guarded(BNC GND ring) on the meter side and unconnected on the kelvin clip side.
the 34401, it is a regular 4mm banana, so you can cut a high-quality banana cable(pomona etc...) and connect it to the kelvin clip.
Title: Re: Kelvin clips
Post by: tszaboo on November 07, 2024, 01:10:13 pm
the 5th wire,  some  are coax shielded and all 4 probes shield are connected together (5th) to a ground body of the instrument

as for efficiency ???
Where do you connect it on your multimeter?
Title: Re: Kelvin clips
Post by: AVGresponding on November 07, 2024, 01:37:44 pm
Solartron 7075 has a 5-pin Fischer or Lemo connector with the guard being one. Some other older meters, like Fluke 8300A iirc just have an extra banana/binding post
Title: Re: Kelvin clips
Post by: tszaboo on November 07, 2024, 02:21:36 pm
Solartron 7075 has a 5-pin Fischer or Lemo connector with the guard being one. Some other older meters, like Fluke 8300A iirc just have an extra banana/binding post
Sure, and the old 3458A at work had that.
How about the Agilent 34401A like the OP has?
Title: Re: Kelvin clips
Post by: Kean on November 07, 2024, 02:44:36 pm
Solartron 7075 has a 5-pin Fischer or Lemo connector with the guard being one. Some other older meters, like Fluke 8300A iirc just have an extra banana/binding post
Sure, and the old 3458A at work had that.
How about the Agilent 34401A like the OP has?

The 34401A and 34465A manuals mention this in the section Low-Level Measurement Errors
Quote
For this reason, you should apply low-level ac voltages to the multimeter through shielded cables. You should connect the shield to the input LO terminal.

For reference, the Keysight Kelvin probe set P/N 11059A uses RG174 cable with the shields terminated to the 5 banana plug (open at the Kelvin clips), and an extra alligator clip at the other end.
They are quite expensive, but I bought mine a long time ago when they were significantly cheaper (but obviously not as cheap as decent Chinese ones).
https://www.keysight.com/au/en/product/11059A/kelvin-probe-set.html (https://www.keysight.com/au/en/product/11059A/kelvin-probe-set.html)
Title: Re: Kelvin clips
Post by: Giallograle on November 12, 2024, 06:51:18 am
Thanks everyone.

After ordering the ETA4551 (Kelvin clips to 4mm plugs, unshielded), I eventually found the ETA3206 adapter plug - 4mm plug to 4mm socket suitable for sheathed connectors - on www.tw-eta.com (http://www.tw-eta.com). ETA has a shop on Taobao where I got them for $1.5 each which will allow the use of the usual test leads across devices.

Lots of other useful leads in a wide range of formats, and test fittings on this site, eg BNC set to SMD so I'm ordering a few more leads.
Title: Re: Kelvin clips
Post by: timeandfrequency on November 12, 2024, 08:02:52 pm
Hello Giallograle,

Check out this small clip with a strong spring (https://uk.rs-online.com/web/p/kelvin-clips/7148263).