DER-EE DE-5000 ESR zero measurement problem.

[TA3UIS]

Hello everyone, I am new to the forum. It's a great forum.

My problem is that the DER EE DE-5000 LCR METER I bought 3 months ago.
Measures the ESR value of 3300uf and 10.000uf capacitors as ZERO.
Where might the problem be? I added a few screenshots.

[mawyatt]

Did you preform an Open and Short Calibration first?

Best,

[TA3UIS]

Hello, yes i dit it but nothing change.

[mawyatt]

OK. Now add a small valued resistor under 1 ohm in series with the large value cap. Measure the resistor first to get it's value, then add in series with cap. Meter should show ESR as value of added resistor plus any ESR of actual cap.

Edit: Just noted your frequency is 100Hz, try 1KHz instead.

Best,

[4thDoctorWhoFan]

Those very high value caps should read about 0.0.
That means those caps are good.  I would be worried if those caps did not measure zero.

Approximately 2200uF and up should read zero ESR.
They are probably actually measuring around 0.01 or 0.02.

[TA3UIS]

I wonder why the DE-5000 does not show the ESR value before adding the resistor, I will test it with a series connected resistor and share the result.

The cheap TC-1 LCR Meter showed the ESR value.
See sample photo.

[mawyatt]

As Dr Who noted, the resolution is only 0.1 ohms at 100Hz for ESR. Try as we suggested moving to 1KHz frequency, here the resolution for ESR is 0.01 ohms.

Just checked a 1000uF at 100Hz and reading shows 0.0 ohms for ESR, then changed to 1KHz and we see 0.02 ohms.

Best,

[TA3UIS]

It gives no value at 1KHz.

[TA3UIS]

Is there a sure way to tell if this is not a problem with the DE-5000?

[mawyatt]

Check the manual, this 3300uF might be out of the range at 1KHz for ESR resolution of 10m ohms. We don't have anything larger than 1000uF, so limited in higher values, but don't think your LCR has an issue.

This LCR meter works by applying a sinewave signal and measuring magnitude and angle of the DUT impedance, whereas the TC-1 uses a pulse technique. Generally the sinewave method is preferred for precision measurements and why the higher end LCR meters employ such.



Best,

[TA3UIS]

I connected 3 pieces of 1ohm parallel resistor in series to a 10,000uf capacitor. ESR measurement was successful.
What would this measurement reveal?

Is DE-5000 good or defective?

[KungFuJosh]

Your meter works fine. All meters have limitations, and right now you're learning the limits of this one.

The purpose of adding a known resistance in series is so that you can subtract the difference to find your ESR. So you need to also measure your resistor(s) separately to know that value. If you add a 1ohm resistor in series with the cap, and you get 1.1ohm reading, your ESR is 0.1ohm.

[TA3UIS]

Your meter works fine. All meters have limitations, and right now you're learning the limits of this one.

The purpose of adding a known resistance in series is so that you can subtract the difference to find your ESR. So you need to also measure your resistor(s) separately to know that value. If you add a 1ohm resistor in series with the cap, and you get 1.1ohm reading, your ESR is 0.1ohm.

As far as I understand, the purpose here is to bypass the limitations of the device, right?
Some kind of hack by connecting a 1ohm series resistor.

[sonpul]

You can view ESR in RS mode.

[KungFuJosh]

As far as I understand, the purpose here is to bypass the limitations of the device, right?
Some kind of hack by connecting a 1ohm series resistor.

More math than any hacking. As sonpul said, you can use Rs mode instead to show ESR without seeing the C at the same time.

For example, in Cs a 2200µF cap shows correctly for me as 2.2mF but ESR says 0.0. In Rs mode it shows 0.02Ω. For comparison, my ST2832 shows Rs as 0.02424, so the DE5000 did fine.

Thanks,
Josh

[Vachik]

It's not a problem DE-5000. That's how it should be. T1 is not a meter LCR!
If you need additional characters (0.0хх), use the mode Rs.
ESR according to specifications, it is usually given at a frequency of 100 kHz.

[TA3UIS]

For ESR measurement only, it seems like a good idea to always measure with RS mode for high-capacity capacitors.

[sonpul]

ESRs of large electrolytic capacitor ratings are more often measured at 100-120Hz. Some Low ESR and polymer ones already have other requirements. E.t.c.

[TA3UIS]

I guess everything is fine and it will be the RS mode that I need to use for high capacity capacitors.
I made two measurements in RS mode at a frequency of 100Hz vs 100kHz and the results were as follows.