Well I just discover an true problem with the Fluke 28II by comparing it with the Agilent U1272A and the Fluke 8050A (bench top) .
And the problem is that the Fluke 28II adds 100mOhm on the 600 Ohms range , because it just does so .
The same thing was happened also at my Fluke 87V and now I know why … because it just does so too.
And why it did bother me ? simply because all those tests that I did on test leads and their tiny resistance,
I was getting an a resistance of 00.15 when I was crossing the leads and I was believing that the meter was saying the truth .
But no it was not !!
The true resistance was 100mOhm less.
And in this example would be 00.050 that is just 50mOhm
I did a simple test by measuring the inner resistance of my own Resistors decade box .
With a fixed set of cables with bananas at the ends.
And the numbers that I got from them : ( with No REL) (cables & switches & bridges)
Fluke 28 II ……………. 0.15 ( High res 20.000 counts )
Agilent U1272A …..….00.049 mOhms (30.000 counts)
And the Fluke 8050A 00.06 (07 fluctuates) (20.000 counts)
And the point is that all of them was measuring about 50 mOhm !!
And I got smokes from my ears , because I had take about a hundred of pictures with measurements so far,
and I had posted them in the EEV for over one year now, with both the 87V or the 28II , and all my measurements today looks wrong.
Are those Fluke meters damaged? , hell no but there is a bug in them ..
Do they measure accurately? Yes if you use the relative first so to manually zero out the resistance of the leads .
And then where is the problem ?
The problem is when you need to measure the resistance of the leads it self.
This additional 100mOhm makes the measurement to look fake.
Is there a cure ?
No there is not, the only thing that I can think of , are that in order to measure the resistance of the test leads,
I will had to use a dual banana bridge on the DMM, so to zero out ( RELative) first , and then to add the leads so to measure their own resistance.
But this sounds crazy too ..
Because even if I need to get close to the correct measurement, this bridge banana it should be made of gold !!
Before you call me as nerd because I care that much about micro ohms, just think what you are when you care that much for the micro amperes.
And now that we got even, I am ready for your comments if you have any.