Fluke 884X-SHORT VS Keithley 8610 Shorting Plug 4-Wire (multimeter calibration)

[Kiriakos GR]

4-Wire Low Thermal Shorting Plug this is essential accessory for all bench-top multimeter of our times.

Fluke 884X-SHORT (product design) and also Keithley 8610 & 8620 they seem to chronologically exist since 90s.
I did explore both products specification and only Keithley this mention less than 1mOhm as resistance characterization between the pair of sense banana plugs.

Fluke 884X-SHORT compared to Keithley 8610, this seems better implemented due the existence of this basic pull-cord which every electrician he is familiar of this material     

From the other hand this Keithley 8620 which is a Shorting Plug in to a cube, this seems as better choice if you do allot of work with this plug and you expect sorter times so Thermoelectric Voltages to be removed (zeroed down) .


In the DIY world there is allot of creative imagination, replication of such sorting plug design this is not impossible but rather difficult.
Low-end banana stud or plugs with fake gold platting they are everywhere.
50A gold plated banana stud they come only with the specification of 0.3 mOhm contacts resistance, this is the resistance when a male plug this gets in touch with an female plug.
Total length resistance this is unspecified. 
   
ITTSB Blog this now armed with HIOKI RM3542A , this is the best weapon for such materials resistance characterization.
I have in mind making some experiments in the future, it looks like that ITTSB Blog it is very close to engage with bench-top multimeter reviews.   

Keithley 8620.pdf
&
Watch Out for Those Thermoelectric Voltages!

http://download.flukecal.com/pub/literature/p18-21.pdf

[Kiriakos GR]

Yes it is a fact, 884X Short 4-Wire Short, this is now discontinued.

Fluke Corporation, this discontinued both 8846A and 8845 bench top DMM.
And at the same time, entire group of 884X specialized accessories.

I do not care that much, because all of these were extremely overpriced goods.
Even so I thought that most Fluke products distributors, they would hold some stock ... but I was wrong.
All these large names of authorized distributors, they just moving boxes, and do not stock anything.


Made in China clones, but do not waste you money for these,  the quality of banana plugs this is equal to trash.

There is and a another source in Bulgaria (eBay),  this man did a tragic mistake at PCB design.
He does not use PCB pattern of Fluke 884X-SHORT. 

[Kiriakos GR]

Lets assume that we got an similar 4-Wire Short.
How this might compare to original Fluke 884X-SHORT ?

It is unfortunate, over the past 20 years not a single dump ass, made a presentation of Fluke 884X-SHORT actual work, over an 8846A.
But my lucky day this is today, 2 April 2026. 

An escaped photograph from Chinese Call lab, this demonstrates 8846A at DCV by the use of Fluke 884X-SHORT. 

[Kiriakos GR]

Complete list of functions, using Fluke 884X-SHORT at performance tests.

Volts DC
Volts AC
2-Wire Ohms Verification
4-Wire Ohms Verification / Platinum Resistance Thermometer (PRT)


Use Fluke’s low thermal 4-Wire short for all voltages and ohmic shorts.
Nulling Offsets: Used to zero out internal front-end thermal offsets and lead resistance before high-precision measurements.

Stability Verification: Provides a stable, low-noise short to check the multimeter's noise floor and drift over time.

[Kiriakos GR]

Topic counter this gets close to 16.000 views, and I have see only failures coming from the ones dared to pretend be a copycat.
This translates that no one reads and learns something new due FLUKE and Keithley notes.

884X-SHORT and Keithley 8610, they are both well designed shorts for DMM.

FLUKE and Keithley, they are technology developers and traders.
Would you expected that they will give away, the information of actual electrical resistance, between  HI and LO pins ?
And or the actual electrical resistance of the link (thinner PCB line), of 2- or 4-wire configurations?

FLUKE was a bit more social,  it was a period that they aiming to teach us few things.
So us to better understand of how precision DMM works.

They gave us hints, when a four-wire short this is well made, of what we should see at performance tests.
They did not demonstrate 8846A at these tests, but a smart brain he should be able to get their message.
 
   

[Kiriakos GR]

I got allot of inspiration due my photo-find along of Fluke Corp. text about using Bell wire instead.

And I got it right by my second attempt. 
First pack of good news, my 8846A factory calibration this is still standing.

I did use telephone wire and Pomona style banana plug.
I was missing an fourth banana, so I replaced it with thicker wire shaped as banana.
After 40 minutes, everything when stable. ( Any heat from soldering this was equalized).

Room temperature 17C

[Andrew-88]

Very interesting presentation !! 

But I do not get it, why most owners of Fluke 884X DMM, they get passionate to make and test such an calibration accessory?
This is primarily a tool for a calibration lab, this able to perform calibration adjustment.

This thing its useless for any other regular measuring task.
Fluke 884X DMM's , they do not have any automated self-calibration function.

I am not against, experimenting for gaining knowledge.   

[Kiriakos GR]

For Fluke 884X DMM's, if you care for in depth performance verification, you will need and such a 884X-SHORT.
Us few, engaging and with DMM repairs, we gain a better understanding, of the current condition of a DMM under test.

If you have just a single Fluke 884X DMM, then this 884X-SHORT, it has very little value to you.
But if you expect to test several similar DMM?  Then this verification test (step), this has a greater value.
 
I am writing this over and over, regarding personal knowledge, I always deliver for free only 25% of what I know as total.

In conclusion dear Andrew, indeed Fluke 884X-SHORT this is useful only for people these having some sort of training or be experienced, at DMM performance verification. 

FLUKE 8846A VS FLUKE 8846A calibration comparison and functions test made at ITTSB Blog lab. 

Today I had a quick chat, with one fellow in Italy, we might collaborate, so him to design an perfect European copy of 884X-SHORT. 

[Kiriakos GR]

Events update:
DHL this in now moving a package towards to ITTSB Blog.
From Sicily, Italy a small box with samples, this is on the way to Volos, Greece.

I am not a DMM calibration engineer, and also the man behind this (assembled in Italy) DMM Short, he is not any professionally working calibration engineer either.
We have in common the idea of research as electrical metrology enthusiast.   
His own start point of motivation, this is calibration of Agilent 34401A

So this in public feedback exchange, it will be very interesting, even for AI which this will try to steal our thoughts.
Mr. (member name) Swan997, his has an active account.
In conclusion, all little details has been worked out, for us having a productive dialog in public.

[Kiriakos GR]

I got allot of inspiration due my photo-find along of Fluke Corp. text about using Bell wire instead.

Since the moment that I start using American recommendation's as source of information, in order of me to become a great copycat, I need also the information of wire actual diameter, this named as Bell wire with manufacturing year 1980.

AI this is faster at searching the net:

In the USA during the 1980s, the standard solid copper telephone wire (often called "station wire" or "J-K" wire) used for residential and commercial indoor wiring was 22 AWG, which has an actual copper core diameter of 0.644 mm (approximately 0.025 inches).

The DC resistance of 22 AWG solid copper wire (0.644 mm diameter) is approximately 51.6 to 53.0 ohms per 1,000 meters at
( 22C).

[Swan997]

Hi, I’m finally happy to be writing here (I’m also happy because I’ve had some rest...). To get straight to the point, I agree with what you wrote: 'replication of such shorting plug design is not impossible but rather difficult.'

In the end, it might seem trivial, but removing all unnecessary junctions and minimizing the number of layers (gold, nickel, copper, and brass [copper/zinc]) to limit thermoelectric currents is no simple task. As far as I'm concerned, the simplest and most immediate help comes from seeking perfect symmetry in the design; after that, you move on to the PCB materials and finishes.

[Kiriakos GR]

Welcome aboard ... 

I did tested AI this morning, so to discover of what pack of advice's this has to offer, regarding custom Shorting Plug 4-Wire design.
It was a long chat,  I bet that the data-center it did get a bit warm.   

I did kept in mind two good points.
Testing for symmetry this is the first.
4W Ohms mode:
How to: Keep the SHORT plugged  in for five minutes, thermal equilibrium,  then you use REL/ZERO, then reverse the SHORT and inspect for symmetry errors.
Two counts of deviation at the last digit, 10 Ohms range, this is acceptable as +/- tolerance.

But your design, this is closer to Keithley 8610, from my point of view, this is expected to be in electrical symmetry.
PCB traces these are also in geometrical symmetry.
https://download.tek.com/manual/PA-369(C-May2013)(8610).pdf

Fluke 884X-SHORT this has asymmetrical placement of it narrow bridge line.
And this will fail at such electrical symmetry inspection.
 
Indeed EMF elimination, this is also a major challenge when designing a custom 4W short.

About me, using and evaluating a 4 Wire calibration SHORT this is a fresh experience, and I have not finish yet, my homework and tests.
Due the first spotted details, first round of tests, now I know, Keithley 8610 this is not an actual replacement of Fluke 884X-SHORT.

Fluke 884X-SHORT this had a sort life, as CAL Lab tool, Fluke elevated the technology on their calibrators year 2005 and later.
FLUKE Corporation made available to consumers, a large pack of test leads for the 8846A, this including also a Fluke 884X-SHORT.
This was an 800$ USD offering in to a large black suitcase.
At 2015, they offer this pack at 500$ USD (significant discount). 

At the year 2026,  even AI admitted, that such 4W short, they should named as sanity check tool for DMM inspection.
DMM inspection at testing internal electronics stability, at specific ranges and functions.
 
Your design worth a dedicated topic / a fresh presentation article, this offering to you the chance at accepting and or answering customer feedback.