Your DER/IET DE-5000, DE-6000, MS5308 has this strange behaviour?

[Nuno_pt]

It would be good to check with an TL-21 mod for Kelvin clips, to see if that change the behavior.
Maybe it's an alligator thing. :-)

[BravoV]

Reading Nuno_pt's comment made me opened and re-checked my clips, and apparently there were problems with my Kelvin clips that made the weird offset  , fixed it and here the 2nd round results.

Suggesting to edit the 1st post's title, add the words "Mastech MS5308", hopefully these owners can share theirs as well here.

[jpb]

@ jpb:

Thanks.

That was my first thought, but we know nothing about its HW.
Let's assume that its HW is unable to discern, then the specifications given by DER are a false.
But what happens with IET, also lies? Remember that they are using the same hardware.

Honestly, I don't know what to believe.


In addiction, another thing that I thought when I read their last answer: How the hell DER can say that my DE-5000 has any problem from measurements made with another meter? It's absurd!

I've not really looked into the claimed specs of the DE-5000 - just read one or two reviews when I bought mine cheap from Japan on e-bay.

But thinking about it, without full kelvin measurement (and I've not even used the guard) I'm not surprised it has trouble. Trying to measure the inductance of 1cm or so of wire by calibrating out the variable inductance of a few cm of wire is probably rather optimistic.

Better results might be obtained by making a solid jig of some sort or using coax with the guard. Your post has inspired me to experiment a little if I get time at the weekend.

[Carrington]

Their last reply:

Hi Javier.

Thanks for your mail.  Do you have our TL-21, Alligtor test lead case and user’s manual?
I wonder why you don’t test by our Alligator test lead case?   
From your photos today, I still did not see it.
Please understand if you do not use our standard accessories from us, you will get wrong test result.

Best regards,
xxx

Well, it is true, for some LCRs you have to specify manually even the probe cable length.
But, I think that enough is enough. I will not continue wasting my time with DER. No more drama.
I answered using the photographs made by "jpb". Does anyone dare to guess what will be their reply?

And when they say: "From your photos today, I still did not see it." They are referring to this test:
https://www.eevblog.com/forum/testgear/strange-behaviour-with-my-de-5000/msg899473/#msg899473
What can I say? I already knew that this would happen.
However, I didn't expect any reply, so I'm surprised...

I didn't do all this for my own interest, I only wanted to make it known.
I hope that everyone will do the same after of detect something wrong on a instrument, especially if it doesn't care to the manufacturer.
In this way, maybe we will invest our money in the right product, and all these rascals do not laugh on us.

If this bug (or whatever) is not a problem  for you, perfect, but now, you know it a bit more.

They will continue making crap, without looking back. But as I did with OWON, I say:
Fool me once, shame on you. Fool me twice, shame on me. (Anaxágoras)

So goodbye forever, DER.

[Carrington]

... apparently there were problems with my Kelvin clips that made the weird offset  , fixed it and here the 2nd round results.

So, was that!

Suggesting to edit the 1st post's title, add the words "Mastech MS5308", hopefully these owners can share theirs as well here.

But the subject title will be very long. Any idea to summarize it a bit?

[Carrington]

I've not really looked into the claimed specs of the DE-5000 - just read one or two reviews when I bought mine cheap from Japan on e-bay.

But thinking about it, without full kelvin measurement (and I've not even used the guard) I'm not surprised it has trouble. Trying to measure the inductance of 1cm or so of wire by calibrating out the variable inductance of a few cm of wire is probably rather optimistic.

Better results might be obtained by making a solid jig of some sort or using coax with the guard.

Your post has inspired me to experiment a little if I get time at the weekend.

Perfect! Go ahead!

[The Electrician]

The results I reported in reply #31 were made using the built-in double-blade contacts, rather than any "Kelvin" clips or other leads.  Has anyone else made the measurement on a 1 ohm resistor this way?

[Macbeth]

Maybe I am missing something here, but surely OP is measuring a circuit and not a component. If I wanted to measure a 1 ohm resistor I would choose the R mode not the L mode? If he wants to measure the L of a piece of wire, then fine - it appears to do what it says on the tin. 

[mos6502]

Maybe I am missing something here, but surely OP is measuring a circuit and not a component. If I wanted to measure a 1 ohm resistor I would choose the R mode not the L mode? If he wants to measure the L of a piece of wire, then fine - it appears to do what it says on the tin. 

No, because any component isn't really a component in real life, but a circuit. That's why we have things like equivalent circuits for capacitors and inductors. You have ESL, ESR, parasitic capacitance, etc.

The meter should not show a change in inductance just because some ESR is added.

[Macbeth]

I will have to do some testing with my DE-5000 tomorrow. I've got TL-21 and TL-22 and I will use this as an opportunity to knock up some proper Kelvin leads too.

I should have some normal through hole 1 ohm resistors and hopefully some 0805 too. It seems the problem doesn't manifest at over 2 ohm?

[BravoV]

Suggesting to edit the 1st post's title, add the words "Mastech MS5308", hopefully these owners can share theirs as well here.

But the subject title will be very long. Any idea to summarize it a bit?

How bout deleting the duplicate word "DE-5000" ?

Old -> "Your DER DE-5000 or IET DE-5000, DE-6000 has this strange behaviour?"

New -> "Your DER/IET DE-5000, DE-6000, MS5308 has this strange behaviour?

[Carrington]

New -> "Your DER/IET DE-5000, DE-6000, MS5308 has this strange behaviour?

To me is okay.


I add a link to the chipsets datasheet:
http://www.cyrustek.com.tw/spec/ES51920.pdf

[edavid]

Suggesting to edit the 1st post's title, add the words "Mastech MS5308", hopefully these owners can share theirs as well here.

But the subject title will be very long. Any idea to summarize it a bit?

How about forgetting the jokey title and making it "DE-5000, DE-6000, MS5308 can't measure 1 ohm resistor"?

I'm not surprised that DER-EE couldn't understand your bug report, I had trouble myself 

[Carrington]

How about forgetting the jokey title and making it "DE-5000, DE-6000, MS5308 can't measure 1 ohm resistor"?

I'm not surprised that DER-EE couldn't understand your bug report, I had trouble myself 

[Carrington]

@ edavid: Please read a bit, before post anything.

[edavid]

@ edavid: Please read a bit, before post anything.

That doesn't help 

[Carrington]

@ edavid: Please read a bit, before post anything.

That doesn't help 

Ok, in such case, have fun looking all the pretty pictures.

[jarvis]

Reading Nuno_pt's comment made me opened and re-checked my clips, and apparently there were problems with my Kelvin clips that made the weird offset  , fixed it and here the 2nd round results.

Suggesting to edit the 1st post's title, add the words "Mastech MS5308", hopefully these owners can share theirs as well here.

From your photo post, what is the wired offset you mentioned ?

[BravoV]

Reading Nuno_pt's comment made me opened and re-checked my clips, and apparently there were problems with my Kelvin clips that made the weird offset  , fixed it and here the 2nd round results.

Suggesting to edit the 1st post's title, add the words "Mastech MS5308", hopefully these owners can share theirs as well here.

From your photo post, what is the wired offset you mentioned ?

Just watch and compare my two measurements photos in this thread, both were calibrated. The 1st one shorted had an offset, I'm not sure what was causing that, but I guess it was fixed when there was a dangling soldering just holding few strands of wires inside the kelvin adapters and also they're so wiggly, once fixed the offset is gone.

[jpb]

I've not got around to experimenting with jigs but to put something positive in for the DE-5000 I've just received some Russian mica capacitors and thought I'd show the measurements which are well within the specs.

I'll need to post in several goes to keep within the 2k limit.

[jpb]

C = 225 pF.

[jpb]

8000 pF = 8 nF example 1.

[jpb]

8 nF example 2.

I have to wait 60 seconds now - to post again.

[jpb]

Finally 100 nF (0.1 uF) or 100000 pF