multimeter shorting block - Page 1
Forum section: electronics / general

author: niner_007
author_rank: Frequent Contributor
timestamp: September 27, 2019, 07:38:04 am
content: I’ve made a shorting block for my 3458As, could possibly work on other meters.Did anyone else make something similar to this? In theory should add very little noise.

author: tszaboo
author_rank: Super Contributor
timestamp: September 27, 2019, 07:49:35 am
content: Someone had a shorting block on this forum, it was using 4mm banana plugs. That makes it compatible with newer meters.

author: MiDi
author_rank: Frequent Contributor
timestamp: September 27, 2019, 10:44:30 am
content: Quote from: niner_007 on September 27, 2019, 07:38:04 amAt least one from texaspyro

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: September 27, 2019, 01:03:10 pm
content: If you use something with banana plugs, watch out for the chrome/nickel/whatever cheap plated ones. The thermals can be awful.

author: maxwell3e10
author_rank: Frequent Contributor
timestamp: September 27, 2019, 04:30:12 pm
content: My shorting wire - a piece of 3/16 copper tubing sawed length-wise with a hack saw and slightly bent out.

author: niner_007
author_rank: Frequent Contributor
timestamp: September 28, 2019, 04:26:53 am
content: Quote from: Conrad Hoffman on September 27, 2019, 01:03:10 pmYes, I hope I won't, banana seems wrong for precision measurements

author: niner_007
author_rank: Frequent Contributor
timestamp: September 28, 2019, 04:46:13 am
content: Finally the proper bare copper version :-DAttached is the gerbers.

author: SilverSolder
author_rank: Super Contributor
timestamp: September 28, 2019, 07:59:47 am
content: What is the principle behind having such a thin track connecting the two sides, rather than a beefier / lower resistance track?Is it to allow the two sides to coexist peacefully despite having slightly different temperatures?

author: ScoobyDoo
author_rank: Regular Contributor
timestamp: September 28, 2019, 08:04:05 am
content: Hello - I purchased a few of these gold plated 3458A shorting plugs on a Metrology & Maker Fair in Germany in 2018 ...Herzliche Grüße/Meilleures salutations/Best regardsScoobyDoo

author: MegaVolt
author_rank: Frequent Contributor
timestamp: September 29, 2019, 03:27:50 pm
content: Quote from: SilverSolder on September 28, 2019, 07:59:47 amThis one is narrow in size. But it works in a different size - wide. Those. the current does not flow in length but in width. As a result, we have very little resistance.QuoteThe temperature distribution along one material does not play a role. It plays the role of temperature near banana contacts.

author: MiDi
author_rank: Frequent Contributor
timestamp: September 29, 2019, 10:15:31 pm
content: Quote from: SilverSolder on September 28, 2019, 07:59:47 amTo zero a 4-wire/Kelvin ohm measurement in principle a short between the two sense lines would be sufficient.In practice this does not work as the instrument detects an incorrect 4 wire measurement and therefore a short between all 4 terminals is needed.As the sense lines carry nearly no current there is no need to have an ultra low resistance short - this is completely different to 2 wire shorts.To have a quick thermal equilibrium a low heat capacity of the short helps.In addition Fluke gives some insights in 4 wire shorts in "Watch Out for Those Thermoelectric Voltages!"

author: VintageNut
author_rank: Frequent Contributor
timestamp: October 13, 2019, 02:40:04 pm
content: Here is the Keithley 8610 shorting blockThese are used to zero out DMMs in 4-wire resistance modeIf you have the ability to actually measure one of these, you will find that the actual resistance is on the order of micro-ohms.If you want to zero out the 1-ohm range of a 7 1/2 digit DMM, you might want to consider the Ohm Labs zero ohm standard. My instance of this device is no more than 4 nano-ohms. It is several orders of magnitude less resistance than the 8610. The Ohm Labs device cost $400 when I bought it a few years ago.I have played around with many different DIY shorting plug devices. The best one is a round disk of solid copper with 4 holes and 4 solid copper Tattoo screws and solid copper ring terminals and solid copper wire. The actual resistance is fairly close to the commercial Ohms Labs device. The DIY device soon becomes tarnished and is a pain to maintain. An improvement would be to gold plate all of the parts.

author: niner_007
author_rank: Frequent Contributor
timestamp: November 15, 2019, 04:34:43 am
content: The shorting block is working very nicely :-)

author: TERRA Operative
author_rank: Super Contributor
timestamp: November 15, 2019, 04:46:10 am
content: I built one that looks a bit like the picture vintagenut posted, but I couldn't find gold banana plugs.If anyone can tell me where to get gold plugs, let me know!

author: Andreas
author_rank: Super Contributor
timestamp: November 15, 2019, 06:12:00 am
content: Hello,I have used those:https://www.conrad.de/de/p/staeubli-sa403-messerleiste-stecker-gerade-stift-4-mm-messing-1-st-730880.htmlwith best regardsAndreas

author: MegaVolt
author_rank: Frequent Contributor
timestamp: November 15, 2019, 09:01:14 am
content: Quote from: niner_007 on November 15, 2019, 04:34:43 amWhat are the readings on the 100mV range

author: TERRA Operative
author_rank: Super Contributor
timestamp: November 15, 2019, 11:48:33 am
content: Quote from: Andreas on November 15, 2019, 06:12:00 amOh, they look nice. Thanks for the link!

author: niner_007
author_rank: Frequent Contributor
timestamp: November 19, 2019, 06:00:00 am
content: Quote from: MegaVolt on November 15, 2019, 09:01:14 amI'm seeing 0 to 90nV variation, basically the last digit, I'm not sure if it's the 3458A (this is an ebay unit I've ran for awhile), or something elseI have NPLC 30, AZERO ON, LFILTER ON and was NULLed of course, if I'm missing a setting, let me know

author: TiN
author_rank: Super Contributor
timestamp: November 21, 2019, 03:14:37 am
content: You guys are all fancy, I just plonk piece of freshly cut solid copper AWG20 wire into posts.No need for LFILTER in DCV mode, and why NPLC30?