Awesome kelvin tweezers - Page 1
Forum section: electronics / general

author: Carrington
author_rank: Super Contributor
timestamp: April 15, 2014, 06:07:59 pm
content: I was looking for kelvin tweezers, and I found this one:http://www.ccti.biz/test_tweezers/test_tweezers.htmlhttp://www.ccti.biz/test_tweezers/Tweezers_App_Notev3.pdf(Performance Data)Awesome...

author: Carrington
author_rank: Super Contributor
timestamp: April 15, 2014, 06:11:33 pm
content: And something more modest (Hameg HZ-19):http://www.rapidonline.com/test-measurement/hameg-hz19-smd-test-tweezers-kelvin-test-lead-4-wire-85-4453Unfortunately I can't find a detailed picture of the tip.Edid: To add a detail picture of the tip.

author: DmitryL
author_rank: Regular Contributor
timestamp: April 15, 2014, 06:59:52 pm
content: Quote from: Carrington on April 15, 2014, 06:07:59 pmDo they have to be so complicated?If current/voltage wires connect near the end of the solid tip, all you need to do is to compensate a couple of mOhms of this tip. Anyway, you'll have to do open/short calibration if you change probe or wish more or less good performance.BTW, it might be problematic to grab 0603, 0402 components with such tips configuraion, IMHO.

author: gxti
author_rank: Frequent Contributor
timestamp: April 15, 2014, 08:47:25 pm
content: The contact between the tweezers and the part is probably the least predictable resistance in the system. If you connect the wires before that point then you can't zero it out.

author: bronson
author_rank: Regular Contributor
timestamp: April 15, 2014, 09:06:22 pm
content: Those look hawt, especially the first. Any idea on cost? I figure when they don't even include distributors on their website, the prices are military grade.I've been half-heartedly looking for some decent <$150 kelvin clips... haven't found any yet. Hoping this thread turns up some.

author: DmitryL
author_rank: Regular Contributor
timestamp: April 15, 2014, 10:06:14 pm
content: Quote from: gxti on April 15, 2014, 08:47:25 pmRelying on tweezers (with unpredictable hand force) to measure something with 0.1 milliOhm (or 0.1 pF) resolution doesn't make much sense to me anyway...

author: Carrington
author_rank: Super Contributor
timestamp: April 16, 2014, 04:46:17 pm
content: Quote from: DmitryL on April 15, 2014, 06:59:52 pmWell all counts.

author: Carrington
author_rank: Super Contributor
timestamp: April 16, 2014, 04:47:07 pm
content: Quote from: gxti on April 15, 2014, 08:47:25 pmYes, in some cases, the open / short calibration does not work.

author: Carrington
author_rank: Super Contributor
timestamp: April 16, 2014, 04:47:30 pm
content: Quote from: bronson on April 15, 2014, 09:06:22 pmNo idea, but they are probably expensive.

author: Carrington
author_rank: Super Contributor
timestamp: April 16, 2014, 04:48:05 pm
content: Quote from: DmitryL on April 15, 2014, 10:06:14 pmI understand what you mean, but in reality all depends on the case, this 0.1 mOhm or 0.1pF can be quite important or insignificant.After a open/short calibration with a distance between tweezers tips of approximately a 603 case.After that, measurement of a 1 pF capacitor (603 case).Fully open Tweezers (such value should be negative).

author: Carrington
author_rank: Super Contributor
timestamp: April 16, 2014, 04:55:00 pm
content: One kelvin tweezer more:http://www.testoon.com/product/test_leads_and_touch_point-f-173/multi-contact-m-51/kpz-bm/p-p-1866.htmlhttp://www.amt.cz/info/5/BNCKP.pdf

author: Gaylord
author_rank: Newbie
timestamp: March 09, 2016, 01:25:37 pm
content: The Kelvin test tweezers made by CCT have now been discontinued. SKG Automation offers high quality Kelvin test tweezers plus several additional high performance Kelvin fixtures.

author: Carrington
author_rank: Super Contributor
timestamp: March 16, 2016, 09:07:19 am
content: Quote from: Gaylord on March 09, 2016, 01:25:37 pmGood to know, thanks for the info.Although, perhaps, the best option in terms of price / ruggedness view are these:http://es.aliexpress.com/item/TH26009C-SMD-Kelvin-test-cable/32504597810.htmlOn the other hand the SKG tweezers, are a beast.