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Active since 7 June 2012  


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Recent Posts

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11
RM3542A this using a Kelvin Clip harness with BNC end point, part code HIOKI 9140-10.
 
The plastic body of the clip started to crack at the jaws, I am keeping these alive by adding super glue at both clips.
They must be replaced in the upcoming months.
This harness it is also overpriced, I am now looking for another solution to improvise by replacing the plastic clip body by retaining clips jaws and cables as is.
Still looking for a solution.

Kelvin clips known as Taiwanese origin (GW Instek) they are good but not great, they seem slippery because their inner grooves at the jaws they are close to be called as flat. 
12
I think the most important thing of the clips is that the contact surface to be much stronger as possible.
And you what kind of clips use for your HIOKI ?
13
I am assuming that KEYSIGHT 11059A which I did touch they are production of 2015 or so.
It seems that they are out there several products of different batch (small changes at its revision).

My problem this is build quality of the clip and longevity this is warranted when they are spring loaded instead using O-rings.
Spesific HIOKI Kelvin clips they have clips design which I think that I can trust for non-flat surfaces.
About specific HIOKI cables softness I have no idea.


14
Maybe you are right about the wires from KEYSIGHT 11059A but mine they are really very flexible and I strongly believe that they are Pomona 5940 and from pictures seem to look better, do not give you the impression of silicone cables but are very flexible.
15
I have use KEYSIGHT 11059A just once.
I disliked the wires, they seem hard and their isolation seemed to be made of hard nylon.

One customer of my, he got those for a Fluke 8846A in my city, the fifth banana this has no actual use at 8846A, if shielding this required for very high ohm measurement then 8846A USB port ground (metal frame) this is the only plug-able section that some one can use. 

Speaking of favorites, this is my favorite cables which I will never buy due their salty pricing.
16
In the past weeks I am still investigating several aspects regarding Kelvin probe for 4-wire Resistance measurements’.

Is cables length important ?
Is wire diameter important ?

My Fluke 8846A benchtop DMM this is fully capable to explore down to 10 Milli-Ohm with four digits resolution ( example 10.42 Milli-Ohm).
In comparison with HIOKI dedicated resistance meter, I did succeed to confirm that FLUKE 8846A actual potential this is a trusted digits resolution down to 10.4 Milli-Ohm, this translates that last digit at 8846A this is dust in the wind.
In other words I can trust 8846A when clips are perfectly zeroed down to 0.1 MilliOhm = 100000 nano-ohm.

8846A this inject low current for resistance measurement starting from high as 5mA (10 Ohms range) and by stepping up ranges this become 1mA and also even lower at 0.1mA etc etc.
Therefore the selection of wire diameter regarding copper this is mostly at serving in favor of mechanical strengths than assistance for a better and a more accurate measurement.

The question of cable lengths this were answered to me by its self,  in order to measure injected test current I had to double my cables length by using extension cables and to use GDS-320 as milliampere meter.
As soon 8846A when zeroed (test leads), measurement accuracy was as expected.  :)

What I am trying to make you realize by all these details, this is that it is more of highest importance the true capability of your measuring device than a Kelvin clips harness (no matter of what is made from). :)

   
   
       
17
I have a set of Kelvin probes for over 25 years, they come from an old HAMEG benchtop. Looks pretty good, the only change I brought was that I added some O-rings over the original rubber to strengthen the jaw contact pressure. I was going to buy some new ones but after this change I decided to keep them. I searched them on the net and found them like:
Pomona 5940 - Kelvin Clip Cable Test Lead Set and KEYSIGHT 11059A Kelvin probe set.
18
One picture = 1000 words.
But what us consumers we are not informed about this is life-cycle of plastic materials in use for test-leads. 

Some factories they deliberately create plastics with limited life-cycle by thinking GREEN, but some others they simply make plastics which will shortly decompose and collapse, so to force consumers spending further more money about buying this product again and again.

A third case of premature death of Kelvin Clips, this is forcing the clamp jaws beyond their mechanical ability (Jaws full open).
A fourth case, this is stepping over it with your shoe.  :)   


I am not a fortune teller, I do not know what happened with specific (HP / Agilent 16089B) clip, but beware to not stressing your Kelvin Clips.  ;)
Naturally I am all ears and eyes for your own Kelvin Clip - Sudden DEATH story (if you have one to share).
     
19
By a high percentage of success, the first SCAM factory in China this is detected.  :P
North Lake Technology Co.Ltd

Now, another competitor factory this teaching consumers to judge product quality by the plating finish and smoothness of metal surface.  :)

My problem this is that at such female 4mm banana plugs, electrical resistance of poor made and decent made by solid copper, this is at the magnitude of  0,20 Milli-ohm ( 1/5 of single Milli-ohm) and even the finest Milli-ohm meter, this can hardly help as SCAM detector by measuring the difference.
 
20
After the discovery that several factories scamming the market by offering recycled aluminum with Gold paint,  I was forced to perform a second quality verification at those accessories which I did gave a positive recommendation.

By removing the nickel plating from both specific items, they are made of Brass which this is what I would expect.  :)

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