Products > Test Equipment
East Tester ET4410 ESR Measure
Martin72:
--- Quote ---To increase the ESR to 1.59 ohms (as per your example) requires an external series resistor of about 1.5 ohms.
Connect such a network to your meter and check the readings at 120 Hz.
--- End quote ---
Tested it with the same electrolytic cap and with 2.7Ohm.
Q decreases, phase is under 80° and ESR value is exactly plus 2.7Ohm(2.96Ohm).
The Electrician:
--- Quote from: indman on July 27, 2022, 09:15:35 am ---
--- Quote from: The Electrician on July 26, 2022, 09:01:40 pm ---Page 41 of that manual shows the adjustment. If that adjustment is taken into account, the behavior of the DE5000 is accounted for.
--- End quote ---
I've read this guide before and it introduces even more questions than answers!
--- End quote ---
Az is not an impedance value--it's a correction factor.
I should have said that it "attempts" to account for behavior. I didn't read all that info carefully because I saw a couple of expressions that one would find in a list of correction factors, but upon reading carefully I see that they have not done a good job. The manual for the ET4410 linked in reply #xx has a much better set of correction factors.
The DE5000 is quite good for ~$100, but it has some serious limitations.
For example I have an 1800 uF 16v cap from this series: www.nichicon.co.jp/english/products/pdf/e-hz.pdf
This is a very low ESR capacitor typical of the sort found on computer motherboards.
Have a look at the spec for impedance at 100 kHz; it's 6.5 milliohms and my Hioki measures it as 6.54 milliohms. The Hioki measures the capacitance as -493.8 uF since 100 kHz is above the self resonance frequency. For measurements of such a low ESR, it's important to insert the capacitor leads fully into the fixture. If I insert the leads so that only the very ends of the leads are in the fixture, the ESR reads 7.78 milliohms.
If I measure it with the DE5000 at 100 kHz, the capacitance value is OL, the ESR value is ------, a bunch of dashes. However, if I set the DE5000 to measure Rs, I get a value of .014, not .0065 as it should be, but at least it gets something. :--
I have a some more handheld LCR meters to try.
The Tonghui TH2822C measures the capacitance at 100 kHz as -372 uF, and the ESR as 7.0 milliohms. I had to do the short compensation to get that value. The value of 7.0 milliohms is .5 milliohms higher than the expected 6.5 milliohms because the plastic case of the meter prevents the capacitor leads from being inserted flush with the contact blades. This is excellent performance.
The Applent AT826 measures the capacitance at 100 kHz as -391 uF, and the ESR as 7.1 milliohms. I did not have to do the short compensation with this meter. This meter has the same problem as the Tonghui--the capacitor leads can't be inserted all the way into the contact blades, giving a reading a few tenths of a milliohm higher.
These two meters are quite a bit more expensive than the DE5000, but they perform much better. The DE5000 performance is not bad for $100, but isn't there some old saying about getting what you pay for?
TimFox:
When measuring such large capacitance values at such high frequencies, fixturing is critical to get an accurate result.
What exact fixture did you use on the DE-5000? (By the way, I would not trust the ESR value under these extreme conditions on my DE-5000.)
I find it perplexing how many people are concerned about accurate measurements of such ESR values; maximum values are normally more important.
Martin72:
--- Quote ---If I measure it with the DE5000 at 100 kHz, the capacitance value is OL, the ESR value is ------, a bunch of dashes. However, if I set the DE5000 to measure Rs, I get a value of .014, not .0065 as it should be, but at least it gets something.
--- End quote ---
Doesn´t wonder me, the chipset the DE5000 use did not specify 100Khz as a testfrequency for such a "large" value.
In the 2000µF range, max. 1khz.
TimFox:
You cheated by reading the datasheet.
It's like affecting a physical situation by doing a measurement.
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