East Tester ET4410 ESR Measure - Page 1
Forum section: electronics / testgear

author: Martin72
author_rank: Super Contributor
timestamp: July 05, 2022, 10:12:02 pm
content: Hi,I´ve ordered a foilcap assortment to rebuild a notchfilter like the one in thesds2000x+ thread.In this case it should be 10nF caps, in the box there are 10pcs, so I started to measure them with my ET4410.While the capacity value is displayed constantly up to the third digit after the comma, the ESR value is floating.It shows something between 7.XXX and 10.XXX Ohms alternating, never stable.I thought, ESR will be caluclated so I wonder why the cap will be stable displayed, the ESR not.And:Taking a different cap, an Elko with 1000µF, ESR is stable displaying.Are the caps bad, is it because of the low value of 10nf...Will investigate it further, with other caps.Martin

author: mawyatt
author_rank: Super Contributor
timestamp: July 05, 2022, 11:22:36 pm
content: Hi Martin,Can you try different frequencies and see if the ESR reading is still bouncing around? Does the meter have an averaging filter that can help?For the Twin "T" Filter in the mentioned thread, the capacitance value is more critical than the ESR and the key is to try and match values of capacitance.Edit: Likely not the 10nF caps. At the notch frequency (~1.6KHz in this case for 10nF and 10K) the capacitive reactance magnitude is equal to the resistance used, so a few ohms compared to 10K isn't going to matter much.Best,

author: Martin72
author_rank: Super Contributor
timestamp: July 05, 2022, 11:34:19 pm
content: Hi,Will do it "tomorrow".QuoteYepp, this here is about the ESR measure behaviour itself- My thoughts viewing your model are, that you´ve measured the ESR to get an more precise model which matches better/can better compared to with the real measured one.

author: mawyatt
author_rank: Super Contributor
timestamp: July 06, 2022, 12:30:11 am
content: Quote from: Martin72 on July 05, 2022, 11:34:19 pmExactly, and why we measured the capacitance and ESR at the expected frequency of the notch, ~1.6KHz for the 10nF and 10K. This allowed an accurate simulation of the filter behavior as compare to the Bode Plot measured result.The SDS2104X+ performed admirably IMO, and your HD should really shineBest,

author: Kleinstein
author_rank: Super Contributor
timestamp: July 06, 2022, 09:21:00 am
content: With foil capacitors the ESR is relatively small. So consider the 10 Ohms more like 0.010 kOhms and you have 2 or 3 stable digits after the decimal.The capacity and ESR (more the invers of it) are measured togehter as a kind of complex number. With a near ideal, low loss (e.g. 0.1% range) capacitor the noise is relatively large in the loss direction, because the absolute loss is small.Electrolytic capacitors on the other end have quite high losses (e.g. up to the 10% range) and ESR and this allows a similar number of stable digits for the capacitance and ESR.

author: Martin72
author_rank: Super Contributor
timestamp: July 06, 2022, 12:50:30 pm
content: Seems plausible.Meanwhile I´ve tried different cap-types, different values, but always foil caps - It´s always the same, no stable values.It´s a pity in this case that I´m not at work for the next weeks for checking it against our other lcrs.

author: mawyatt
author_rank: Super Contributor
timestamp: July 06, 2022, 01:01:17 pm
content: Might be an issue with that particular instrument, or the actual design. We just measured a cheap 10nF film cap with the DE-5000 and get reasonably stable ESR readings at 1KHz, 10KHz and 100KHz after a few seconds.9.9944nF 61.6 Ohms @ 1KHz9.877nF 9.48 Ohms @ 10KHz9.710nF 2.16 Ohms @ 100KHzAlso should add, these type instruments measure the magnitude and phase of the Voltage across the DUT and the Current thru the DUT, then compute the Capacitance and Series Resistance, so believe the ESR is not directly measured but computed.Best,

author: Kleinstein
author_rank: Super Contributor
timestamp: July 06, 2022, 07:08:31 pm
content: The 47 nF capacitor at 1 kHz has an impedance in the 3 kOhms range. So 1 Ohms ESR is just 0.03 % of the impedance. Depending on how good the implementation is, this may be just a limitation of the instrument. If not careful with the wires on may get parasitic effects, that may look a little like ESR, e.g. from inductive coupling.The resilts from Mawatt don't look reasonable - could be a calibration problem, or an extremely poor old MP capacitor with high loss. So even if the readings are stable this would not help as they are way off for a film capacitor - maybe an X7R THT part that looks like a film cap ?.

author: Martin72
author_rank: Super Contributor
timestamp: July 06, 2022, 07:29:47 pm
content: I´ve checked this also with a fixture:https://www.sourcetronic.com/shop/de/lcr-adapter-26048a.htmlTo minimize parasetic inductive effects, same result.

author: Martin72
author_rank: Super Contributor
timestamp: July 06, 2022, 07:56:15 pm
content: Edit:Tested all displayable parameters on a 8.2µF MKP.Stable readings by capacity, phase angle, capacitive resistance, D-Factor(OK, it´s the last digit that is changing a bit).Unstable, really bouncing: ESR and Q-Factor.Will test it further with all the caps I can find here...in the next days..#Martin

author: mawyatt
author_rank: Super Contributor
timestamp: July 06, 2022, 08:10:41 pm
content: Quote from: Kleinstein on July 06, 2022, 07:08:31 pmDon't think we have calibration problem, nor bad capacitors. All instruments calibrated and using an unused new stock WIMA Style Yellow 10nF film capacitor.Freq Hioki IM3536 with Kelvin Clips Tonghui TH2830 with Kelvin Clips DE-5000 with Alligator Clips10KHz 9.99574nF with 15.5464 series R 9.99353nF with 15.6286 series R 10.007nF with 14.85 series RBest,

author: mawyatt
author_rank: Super Contributor
timestamp: July 07, 2022, 05:50:56 pm
content: Just a thought, can you use a lower output resistance than 100 ohms? Might help stabilize the ESR readings.Edit: Also try a higher drive voltage if you can change this.Best,

author: Martin72
author_rank: Super Contributor
timestamp: July 07, 2022, 06:48:30 pm
content: Hi,Can do, will do..Martin

author: TimFox
author_rank: Super Contributor
timestamp: July 07, 2022, 07:12:09 pm
content: Quote from: mawyatt on July 06, 2022, 01:01:17 pmI believe that this type of instrument, evolved from the classic G-R Digibridge, measure the in-phase (“real part”) and phase-quadrature (“imaginary part”) of the voltage across the DUT, phase reference from the drive voltage (or the current through the DUT?) and divide by the device current to get the real and imaginary components of the DUT’s (complex) impedance, so the ESR is determined reasonably directly, rather than from the sine of a small angle.

author: Martin72
author_rank: Super Contributor
timestamp: July 13, 2022, 06:43:58 pm
content: QuoteYou will always get stable values when testing electrolytic capacitors and always "unstable" vaues when testing foil-caps...No, not at all.There is a trend to watch, by many of my foilcaps (MKP, FKP) the ET4410 reads a phase of -90° exactly or really near by (89.95..99).I got some MKT (audio crossover purposes), it´s the same thing but they have losses when using measure frequencies from 10Khz on.Then the phase lowers slightly down to say -88...-89° and the ESR value becomes stable.All electrolytics here got a phase of -72...-87° and the ESR value is stable.Martin

author: Martin72
author_rank: Super Contributor
timestamp: July 14, 2022, 08:47:06 pm
content: Today 10nF glimmer caps arrived with 1% tolerance.Same as all before, capacitance and Xc values are stable displayed, ESR not.The unstable values are annoying and at the end useless.edit: ESR pic titles wrong

author: mawyatt
author_rank: Super Contributor
timestamp: July 14, 2022, 09:35:14 pm
content: Quote from: Martin72 on July 14, 2022, 08:47:06 pmThose 10nF 1% caps look nice, but can't say much about the Easy Tester. What are the ESR specs on the caps?Think this is something to do with trying to establish the ESR with an impedance angle of close to 90 degrees, whatever method is utilized. Altho other LCR meters we have like the handheld DE-5000, or Lab type TH2830 and IM3536 don't seem to have this problem.Maybe others with the same Easy Tester can check with a film 10nF cap??Best,

author: Martin72
author_rank: Super Contributor
timestamp: July 14, 2022, 09:53:29 pm
content: According to theSpecs, loss factor is about 0.001 at 1khz.

author: Martin72
author_rank: Super Contributor
timestamp: July 14, 2022, 10:24:36 pm
content: Thinking further about...When tan phi is 0.001 (specs) and capacitiy is 9.939nf at 1khz(measured), ESR is about 16.949 ohms calculated, see pic with formulars below.Other calculation then:Tan phi is ESR/Xc, take the calculated ESR before and then take the measured Xc on 1khz of 16.014kOhm, its about 0.00106 - It makes all sense.The ET4410 should measure an ESR about 16...17 Ohms, but it didnt, it measures way to less and very unstable.Because:The ET4410 don´t know what we know, the tan phi according to the specs.So how do the ET4410 determine the ESR...And is it only a prob of this puppy ?Maybe not...

author: mawyatt
author_rank: Super Contributor
timestamp: July 14, 2022, 10:48:11 pm
content: Thought you had a DE-5000? If so, how does it behave with these caps?Best,

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 14, 2022, 10:52:03 pm
content: Your problem is undoubtedly a matter of signal to noise ratio.LSR meters operate as Timfox explained in post #13. You can also find a good in depth explanation in the Agilent Impedance measurement handbook. Google "impedance measurement handbook"When you measure a capacitor, the meter applies a sine wave of whatever the nominal voltage is (1 volt for your measurement) and extracts the in phase and quadrature components of the resulting current. The ratio of the two components is equal to the value of D.So if your capacitor is low loss, the real part of the current is going to be very small. For example, if the cap has a D of .001, the meter will be trying to measure a very small current/voltage (microvolts). When the measured value of D < .001 (or equivalently, Q>1000), low cost meters are going to have problems.A good meter will know when it's measurement is in the noise, and will not show very many digits for the result. Watch out for that clue that the measurement is "iffy". For example in reply #9 your measurement shows 4 digits for the capacitance, but only 2 digits for the ESR.In reply #15, the 10 kHz measurement of ESR shows a value of .0085 ohms. This is impossible. The value of Q is Xc/ESR; that measurement would imply a Q of about 188000.The Hioki IM3570 can be set to show 7 digits. This is well beyond the accuracy of the instrument but it's handy for matching components, and watching drift with temperature. Here's what I get when I measure a 10 nF silver mica capacitor, which is a very low loss capacitor, at 10 kHz:The capacitance is shown as 7 digits, but only about 5 of them are stable. ESR (Rs) is shown with 6 digits, but only the leading 2 digits are stable. Note that the Q is about 6000; this is approaching the capability of the instrument. When the Q>10000, the Hioki won't even show a value; it just indicates an out of range value.I think that your East Tester just can't cope with very low loss capacitors. I've noticed that some of the hand held meters I have exhibit the same limitations.

author: Martin72
author_rank: Super Contributor
timestamp: July 14, 2022, 10:53:38 pm
content: @mawyattYou take the knife, hit it in my heart and turning it around....I´ve sold it not long time ago and I could bite in my a*** I did it...

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 14, 2022, 11:43:53 pm
content: Quote from: Martin72 on July 14, 2022, 10:53:38 pmI measured the silver mica cap from reply #20 on my DE5000. Here's what I got.At 1 kHz, the value of the cap is good. D is 0.000, Q is OL, ESR is 1.86At 10 kHz, the value of the cap is correct. D is 0.000, Q is OL, ESR is 0.18These two ESR values for this very low loss capacitor are completely bogus. It's too bad the DE5000 doesn't recognize that it's bogus and refuse to show a value. This is very misleading behavior. A user of low cost LCR meters needs to know that as soon as the value of D is less than .001, the measurement will be noisy. The Gold standard LCR meter is the Keysight E4980A (@ $20000) which can get measurements down to a D of about .0001 with maybe 50% accuracy at the limit.Your East Tester is better than the DE5000.I found a 10 nF polystyrene capacitor and measured it with the Hioki IM3570:This capacitor is somewhat beyond what even the top of the line Hioki can do. Notice that the capacitance is still given with 7 digits, but the ESR (Rs) has only one stable digit, and it is suspect. The DE5000 and other handhelds and even low cost bench meters won't be able to measure ESR of such low loss capacitors; but they can still correctly measure the capacitance.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 14, 2022, 11:57:35 pm
content: Quote from: Martin72 on July 05, 2022, 10:12:02 pmThe measurement is stable with electrolytics because they are lossy; their D is never going to be as low as .001, or even close to that.

author: Martin72
author_rank: Super Contributor
timestamp: July 15, 2022, 12:03:02 am
content: QuoteYap, it´s not the badest one as it got 16 selectable frequencies up to 100khz, output up to 2Vrms, Bias, 30 or 100Ohm selectable output resistance and finally a basic accuracy of 0.2% .And the basic RCL measures it performs very well, but the "secondary parameter" thing...A look into the ET4410 offers a good design of the circuits, but you can´t get schematics for it.As I´ve asked for it, they (East-Tester) immediately send me the SCPI commands.Now I´ve asked of the ESR thing at the beginning of the week and nothing happens.

author: Martin72
author_rank: Super Contributor
timestamp: July 15, 2022, 12:04:52 am
content: Quote from: The Electrician on July 14, 2022, 11:57:35 pmYap, seehttps://www.eevblog.com/forum/testgear/east-tester-et4410-esr-measure/msg4297858/#msg4297858

author: mawyatt
author_rank: Super Contributor
timestamp: July 15, 2022, 12:41:38 am
content: Likely our ESR readings are also stable due to capacitor loss. These cheap film types we have are nowhere near the Q of the Silver Mica or Polystyrene types. Here's what the Tonghui TH2830 and Hioki IM3536 show at 10KHz for a 10nF cheap film type.Best,

author: TimFox
author_rank: Super Contributor
timestamp: July 15, 2022, 08:17:22 pm
content: A comparison of results with my DE-5000 using a home-built four-terminal sense of two binding posts (0.75 in spacing).DUT: SBE 715 (now CDE), 10 nF/5%/600 V film-foil polypropylene ("orange drop") radial leads.Test mode: series capacitance CsManufacturer's spec: Q > 3400 at 20 kHz, Q > 2500 at 100 kHz.100 Hz: 9.932 nF Q = "OL" ESR cycles from 10 to 130 ohms120 Hz: 9.929 nF Q = "OL" ESR cycles from 5 to 56 ohms1 kHz: 9.927 nF Q = "OL" ESR cycles from 0.02 to 0.3 ohms10 kHz: 9.925 nF Q = "OL" ESR stable at 0.01 ohms100 kHz: 9.921 nF Q = 1911 ESR stable at 0.08 ohmsThe "cycling" ESR behaves like a relaxation oscillation between the limits.The last (finite) Q display settled to that value after maybe a dozen readings.The stable ESR values settled after only a few readings.Obviously, this high-Q part is at the limit of loss reading for this meter.Phase angle is always 90.0 deg.

author: indman
author_rank: Super Contributor
timestamp: July 15, 2022, 08:38:31 pm
content: Quote from: The Electrician on July 14, 2022, 11:43:53 pmNow I'm starting to understand why the DE-5000 can't correctly measure high quality film capacitors at different frequencies. Can you measure similar capacitors on your Hioki IM3570 and confirm my findings in this thread?https://www.eevblog.com/forum/testgear/any-one-mod-the-de-5000-for-1mhz-frequency/msg2676075/#msg2676075

author: Martin72
author_rank: Super Contributor
timestamp: July 15, 2022, 08:52:49 pm
content: Come on, not again...

author: indman
author_rank: Super Contributor
timestamp: July 15, 2022, 08:56:30 pm
content: Martin72,Why are you so annoyed? No one has ever given me a reasonable explanation for this device behavior.

author: Martin72
author_rank: Super Contributor
timestamp: July 15, 2022, 09:58:28 pm
content: I don´t think this is really an issue, it goes more in the direction couldn´t get any better.The DE5000 is an fantastic measure device for its price - when you´re basically interested on the main values like L,C,R...I´ve did "tons" of measures comparing to calibrated LCRs, it never fails.The ET4410 got better accuracy, is 3-times more expensive, did some things better . but seems to have "problems" similar to the DE5000 and other cheap LCRs.But let us see what this thread will bring more on informations, which could eventually "used" for understanding the DE5000.

author: TimFox
author_rank: Super Contributor
timestamp: July 15, 2022, 10:10:22 pm
content: For the quite reasonable price, my only problem with the DE-5000 is that when measuring a capacitor or inductor above its self-resonant frequency, it does not indicate negative capacitance or inductance. For that application, I wish it had R and X (with sign) direct readout. I learned decades ago not to trust the “minority” component’s accuracy (e.g. ESR for good capacitor) when Q > 1000 on not-super-expensive equipment.

author: Martin72
author_rank: Super Contributor
timestamp: July 15, 2022, 10:31:09 pm
content: Yep,And a closer look to the "chipset" of the DE5000 offers some informations, how it works and where the limitations are.BTW, this chipset is used by several brands, even on those who cost more than double.When you want "more", you must pay more.

author: indman
author_rank: Super Contributor
timestamp: July 16, 2022, 06:54:53 am
content: Quote from: Martin72 on July 15, 2022, 09:58:28 pmYour explanation is not convincing to me, I'm sorry. A device that claims to measure secondary parameters Q, D, ESR, tg on a par with the primary parameters and cannot be trusted to make these measurements is NOT A MEASURING DEVICE! And I don't care about the cost(price) if the manufacturer can't guarantee the real specifications.

author: Martin72
author_rank: Super Contributor
timestamp: July 16, 2022, 12:02:59 pm
content: Therefore I said not again...We can discuss about in one of the DE5000 threads, here it´s off-topic.

author: indman
author_rank: Super Contributor
timestamp: July 16, 2022, 02:12:12 pm
content: Then eliminate the mention of the DE-5000 from every 2nd post in this thread and ban others from mentioning it in comparative measurements! What difference does it make what is the name of the LCR measuring device if we are discussing the principle of its operation? We speak different languages, alas.

author: Martin72
author_rank: Super Contributor
timestamp: July 18, 2022, 11:12:04 pm
content: Meanwhile I´ve "studied" some methods of ESR measuring....interesting.This brings me to the point to know how the ET4410 measures ESR and why it´s so "bouncing".Last can depend on the noise, no, better, will depend.Therefore I begin to draw a schematic for the ET4410, starting with the output stage.Maybe on this way I find also a "solution" also for the famous DE 5000 and can make people happy, who are expecting everything from a 100 bucks instrument like having one for 1000 or more.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 19, 2022, 03:39:37 am
content: Quote from: Martin72 on July 18, 2022, 11:12:04 pmThe phrase "methods of ESR measuring" spans several kinds of instruments.Meters designated "ESR meter" are very specialized and generally only measure the ESR of capacitors at 100 kHz, and typically electrolytic capacitors of more than 1 uF. They can't measure inductance, or ESR at frequencies other than (typically) 100 kHz. For information on those types of meters see this website:http://kripton2035.free.fr/esr-repository.htmlMeters designated "LCR meter" or "impedance analyzer", if they are modern digital instruments, make measurements using the methods described here:http://kripton2035.free.fr/LCR%20meters/lcr-theory.htmlThere is more information on these meters here:http://kripton2035.free.fr/lcr-repository.htmlWithin this repository there is info on so-called "LC meters" which use yet another technique.Your ET4410 is a full-fledged "LCR meter" and the reason for the "bouncing" ESR reading is what I already explained in reply #20. Even though it is low cost, the DE5000 uses the same technique described in the references in:http://kripton2035.free.fr/LCR%20meters/lcr-theory.html,and its limitations are mainly due to signal to noise ratio.

author: Martin72
author_rank: Super Contributor
timestamp: July 19, 2022, 02:34:06 pm
content: Thanks.Nevertheless I want to try it out making a schematic, today I finished the output stage.(Resistor values are not correct, except the output)Edit: Added signals from PA4 and PA5 of the controller.

author: Martin72
author_rank: Super Contributor
timestamp: July 20, 2022, 10:25:55 pm
content: Man, it´s getting more and more difficult...Problems identifying sot23, is it a diode, a transistor...Signal out path to the Hi-pot/cur socket was easy, but the way back....6 pcs CMOS switcher circuits, several OPs, tons of resistors/caps...It´s much more complicated than on DE5000, therefore it wonders me a little bit having the problems.It´s a pity holidays are going to end, otherwise I can test on monday with the lcrs at work.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 20, 2022, 11:30:20 pm
content: Quote from: Martin72 on July 20, 2022, 10:25:55 pmAre you doing all this tracing circuitry in the ET4410 to try to figure out how it works?To know how a particular meter calling itself an "LCR meter" works, only a few clues are needed. If it applies a sine wave to the DUT, which you showed the ET4410 does in reply #39, and if it allows the user to choose the frequency used to test the DUT, and if the frequency range covered is fairly large, then the method used is almost certainly the ones shown here:http://kripton2035.free.fr/LCR%20meters/lcr-theory.htmlThe commercial so-called "ESR meters" all (with one exception as far as I know, the Capacitor wizard) use pulse or square waves of 100 kHz (some DIY "ESR" meter projects may use a slightly different frequency, such as 40 kHz) . They don't allow the user to choose the frequency of measurement, and they can't make a measurement on a capacitor of less than about 1uF.

author: Martin72
author_rank: Super Contributor
timestamp: July 21, 2022, 12:15:59 am
content: QuoteYes and no.How it works I know, but I want to know more exactly to find out where the problem lies - And maybe "correct" it.You can supply up to 2Vrms into the DUT, that´s way more the most LCRs offers and we´re talked about signal to noise ratio why the ESR thing "sucks".Also you can change output resistance, bias level..The ET can do things other cheapos can´t and you probably got an idea why the ESR measure´s annoying me.Some posts before, the ET measure the most things right and if it would "know" the tan-phi, it would display the ESR correct, because all other measured values are correct.What the cap wizard concerns I agree that this is not a good example because of the fixed frequency which make comparisons useless under the 100khz and because the capacitor limitations.

author: mawyatt
author_rank: Super Contributor
timestamp: July 21, 2022, 12:58:12 am
content: Quote from: Martin72 on July 20, 2022, 10:25:55 pmPlease remember the DE-5000 utilizes a highly integrated chip set, apparently the ET4410 doesn't. This chip set integrates much of the circuitry required to perform the LCR measurements, although don't know the details since we've never designed with this chip set.Best,

author: Martin72
author_rank: Super Contributor
timestamp: July 21, 2022, 01:29:39 am
content: I hoped someone come to argue this way..I know about the 2-Chipset on the DE (and other brands), chances are high that in the end there´s nothing really different except output and bias.We´ll see.

author: Martin72
author_rank: Super Contributor
timestamp: July 25, 2022, 08:48:49 pm
content: Hi,Today I took one of the glimmer caps to work and measure it with our calibrated LCRs..A little surprise (for me):The sourcetronic showed a value at 1khz lower as the ET4410 did (appx 3 Ohm vs 4.9) and a little bit unstable...The keysight U1733C you can completely forget, it "freaks out" by the attempt to show the value(Display blinking).The ET4410 cost about 350€, the keysight 700€ and the sourcetronic 1200€.All seems to have in common that they can´t measure the ESR of foilcaps correctly.Interesting in a negative way..In the next days I´ll measure a electrolytic cap on all the three, if there are remarkable differences between them.

author: TimFox
author_rank: Super Contributor
timestamp: July 25, 2022, 10:04:03 pm
content: Some more quantitative values for your "glimmer capacitors" at 1 kHz.10 nF at 1 kHz has a reactance of 15,900 ohms.With an ESR value of 4 ohms, that is a very highQ= 4000.That corresponds to a phase difference (from the ideal 90 deg) of only 0.014 deg, which is obviously difficult to measure given your measurements (and mine on the DE-5000).I once discussed this problem at a trade show with an engineer at SBE, who worked with pulse-rated polypropylene capacitors that have absurdly highQvalues for high-current applications.He said they had to go to calorimetry to measure the loss of their units: run AC current through them and measure the temperature rise.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 25, 2022, 10:57:40 pm
content: Quote from: Martin72 on July 25, 2022, 08:48:49 pmWhat is a "glimmer" capacitor?It's not that they can't measure the ESR of foil capsgenerally; they just can't measure the ESR of very low loss foil caps.With all the measurements of ESR, also measure D or Q. If D<.001, or Q>1000 you can expect lower performance meters to have trouble.The meters you are comparing can probably get better correspondence among measurements if you were to use foil caps with more loss. Find a foil cap with d>.01 or Q<100 and measure that cap on all three meters.See if you have any mylar capacitors on hand; they are usually fairly lossy.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 26, 2022, 12:50:57 am
content: I found a couple of capacitors, one of ordinary loss, and the other is low loss.Those measured values I'm relying on to be accurate were made on a Hioki IM3570.Capacitor A has a D value of .00135 at 1 kHz, and a D value of .0025 at 10 kHz.Capacitor B has a D value of .000184 at 1 kHz, and a D value of .000256 at 10 kHz.Capacitor A was chosen because its D value of .00135 is slightly larger than .001, which is where the low performance (cost) meters will begin to have trouble getting a good measurement. What I mean by "have trouble" is that the measurement of secondary parameters D, ESR, Q will be incorrect or noisy (fluctuations in the measurement digits).I would expect that low performance meters will be able make reasonably accurate measurements of Capacitor A, but they will get bogus results for capacitor B, whose D value of .000184 is substantially less that the threshold of .001Here are some measurements of these two capacitors made with a high performance meter (Hioki IM3570), and a popular low cost meter (DE5000):Code:Hioki IM3570 DE5000@1kHz @10kHz @1kHz @10kHzC 10.435 10.409 10.446 10.419ESR 20.4 3.90 19.3 3.51Capacitor A D .00135 .0025 .001 .002Q 735 393 785 434Hioki IM3570 DE5000@1kHz @10kHz @1kHz @10kHzC 10.268 10.267 10.269 10.274ESR 2.84 .396 1.03 .16Capacitor B D .000184 .000256 .000 .000Q 5450 3920 OL OLCapacitor A has a 1 kHz value of D of .00135, which is somewhat larger than the threshold value of .001, and we see that the values measured by the DE5000 are quite comparable to those obtained by the Hioki.Capacitor B has a 1 kHz D value of .000184, which is quite a lot smaller than the threshold; we should expect that the values obtained by the low performance DE5000 would be considerably in error, which they are.These experimental values show that low loss capacitors can't be correctly measured by low performance (low cost) meters. The user should always measure D or Q as well as ESR. If the D or Q values are beyond the threshold values of D<.001 or Q>1000, expect that the measurements will be substantially in error. IF the capacitor being measured is very low loss, low performance meters may not be able to make any measurement at all, or will return totally bogus results.Even if the value of D is not checked, the fact that the ESR value is unstable means that the capacitor being measured is very low loss, and if the meter is a low performance unit, the measurements may be wrong. The front end noise of the meter is contaminating the measurement. You just can't correctly measure secondary parameters of a very low loss capacitor with a low performance meter, although the capacitance measurement will be good.

author: MegaVolt
author_rank: Frequent Contributor
timestamp: July 26, 2022, 08:15:42 am
content: Introducing a small additional series resistor can help stabilize the result.

author: Martin72
author_rank: Super Contributor
timestamp: July 26, 2022, 05:29:21 pm
content: Quote from: The Electrician on July 25, 2022, 10:57:40 pmThe german word for "Mica", sorry for not translating that.https://www.reichelt.de/de/en/mica-capacitor-10-nf-100-v--1--cy-22-5-10n-p42453.html?GROUPID=3158&START=0&OFFSET=16&SID=94c8b836af2ba4924e602b770031c41804c22b97609adc734fdca&LANGUAGE=EN&&r=1These ones ans then 10nF.

author: mawyatt
author_rank: Super Contributor
timestamp: July 26, 2022, 06:06:34 pm
content: A few days ago we ordered some high "Q"filmcapacitors since we had none on hand, these were some Polystyrene, Molded Mica, Dipped Mica and few of the Polyproplyene and a film mixture. We had some Polyester or Mylar types already, and various ceramic types including NPO/COG.To evaluate these high "Q" types we had just received we use the Hioki IM3536, Tonghui TH2830 and DER-EE DE-5000 LCR meters. Attached in the page from our notebook to browse thru, and all measurements were done at 100KHz within each meter's range.The 1nF Polystrene has a very high Q of ~10,000 (D of 0.0001) and even caused the IM3536 to flicker into a Display Out of Range condition which occurs at D of 0.0001. Although the IM3536 remained reasonably stable with all the tests, the TH2830 was't quite as good with a bit more randomness and not reading as high a "Q" as the IM3536 (averaging was employed to help stabilizes the IM3536 & TH2830 meters, the DE-5000 doesn't have this option setting).You can see the good correlation between all meters in capacitance readings everywhere, but no so well with the ESR and subsequently D and Q with high "Q" types. At the bottom are the Mylar and Polypropylene types and the meters agree reasonably well with these lower Q capacitors as has been previously mentioned.Best,

author: indman
author_rank: Super Contributor
timestamp: July 26, 2022, 06:15:48 pm
content: Quote from: Martin72 on July 16, 2022, 12:02:59 pmNow it's allowed to mention DE-5000 again in this thread, several times in a row? Was it not long ago that I was forbidden to do this?

author: Martin72
author_rank: Super Contributor
timestamp: July 26, 2022, 07:30:04 pm
content: I think you know how it´s meant.@mawyatt:Interesting that even the hioki won´t be "flawless".The Tonghui is the same LCR like the ST2830 we got.I must read the ST manual again, also the one of the keysight - But i´m pretty sure that there are no remarks in it about the limitation of the ESR (Rs) measure.Same on the ET4410 and of course DE5000.So the conclusion could be that we can´t expect proper ESR/Q readings for every cap-type on the "cheapos" up to the costs of a TH/ST LCR...Hmm.

author: indman
author_rank: Super Contributor
timestamp: July 26, 2022, 07:35:49 pm
content: Quote from: Martin72 on July 26, 2022, 07:30:04 pmIn this case, non-TH/ST LCR devices cannot be considered full-fledged METERS, but should be transferred to the category of AMATEUR DISPLAY METERS with random readings.

author: mawyatt
author_rank: Super Contributor
timestamp: July 26, 2022, 07:47:46 pm
content: Quote from: indman on July 26, 2022, 07:35:49 pmThat's totally ridiculous!!Like saying that a HP34401, KS34465, DMM6500 are "AMATEUR DISPLAY METERS" because they can't read a waveform with very high peak to RMS values as well as the Keysight 3458A!!These are instruments that must be used and understood properly rather than blindly applied, just like the high resolution DMMs mentionedBest,

author: indman
author_rank: Super Contributor
timestamp: July 26, 2022, 08:04:11 pm
content: Quote from: mawyatt on July 26, 2022, 07:47:46 pmNot convincingly.It is ridiculous, this is when the specification for the device specifies the range and the possibility of a full-fledged measurement of secondary parameters with a certain stability and reliability, but in fact this is not provided.If this is stipulated in the documentation, as for HP34401, KS34465, DMM6500, then this is another matter

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 26, 2022, 08:24:11 pm
content: Quote from: mawyatt on July 26, 2022, 06:06:34 pmOne of the things I like about the Hioki meters is their ability to display 4 parameters at once. Try setting yours to match how I did it in reply #20. Then choose the "set" mode, followed by "freq". This allows you to quickly switch frequencies and watch the effect on all those parameters. The polystyrene cap I used has its minimum D around 1 kHz; the Q is way over 10000, so the indication is "Disp out". The capacitance value has 6 stable digits, but ESR has only 1 stable digit--all the less significant digits are bobbling like crazy if the speed is set to "slow". This "bobbling" of the less significant digits is a clear indication that the reading is down in the noise because that is what bobbling digits are--noise.The most stable and accurate readings can be obtained if the speed is set to "slow2", and the level is set to "5V". Also setting averaging to 256 helps a lot for accuracy. Without averaging, I get 1 stable digit for the ESR of the polystyrene capacitor, if I average for 256 times, I now have 3 stable digits, but their accuracy is still subject to the instrument specification.So, Martin72, there's nothing wrong with your meters, you just have to know what it means that for some parameters like ESR, when the less significant digits are bobbling. Those digits are simply measuring noise; the meter has been asked to make a measurement near its capability limit. It's too bad the meter isn't smart enough to always know when to not show noise digits. Your East Tester tries--only showing 2 digits for the ESR is its attempt to not mislead the user into thinking the result is better than it is.

author: Martin72
author_rank: Super Contributor
timestamp: July 26, 2022, 08:40:02 pm
content: Hi,I understand this, you, mawyatt, TimFox and other help to make clear the priniciples behind, now I KNOW it´s not a failure or somekind of mystic behaviour.The conclusions are, that you could use the mentioned "cheaper" meters here well for all purposes, but you should have in mind that they couldn´t measure all possible cases, in this case caps with high Q, their ESR.Even more expensive one can´t do that proper, it needs "more"..To say oh if they can´t do it in every case, they shouldn´t do this in general is not OK.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 26, 2022, 09:01:40 pm
content: Quote from: indman on July 26, 2022, 08:04:11 pmThe manual that came with my DE5000 does not do a good job of specifying accuracy under all conditions. It does not provide an accuracy adjustment to deal with the effect of low loss on capacitor measurements. However, the manual for the IET labs version of the DE5000 does show that. Their manual is at:https://ietlabs.com/pdf/Manuals/DE_5000_im.pdfPage 41 of that manual shows the adjustment. If that adjustment is taken into account, the behavior of the DE5000 is accounted for.The low cost meters are not as well specified as the more expensive ones for sure, and that is a downvote against them. I wish all users of low cost LCR meters would read this thread and not fool themselves into thinking that just because their meter shows a lot of digits that all those digits are meaningful.

author: mawyatt
author_rank: Super Contributor
timestamp: July 26, 2022, 09:03:56 pm
content: Quote from: The Electrician on July 26, 2022, 08:24:11 pmThis is generally pretty much how we have the IM3536 setup with Cs, Rs, D and Q for capacitors, but with 16 averages (trying to keep the IM3536 and TH2830 similar in settings). Haven't tried 256 averages yet tho.Really like the IM3536 but also miss the ability to have a display that shows a frequency sweep on the instrument. Not a fan of having to hang a laptop off everything to "see" decent plots, and since we are dominantly Mac based, much of the support software is not Mac compatible!!These polystyrene caps are generally really high "Q" types, wonder why they are not more popular now (know about the temperature limit), recall they were more popular back a few decades ago.Best,

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 26, 2022, 09:23:51 pm
content: Quote from: Martin72 on July 26, 2022, 07:30:04 pmOn page 18 of the manual:https://www.easttester-cn.com/uploads/ET44-Benchtop-LCR-METER-for-Component-Measurement-User-Manual.pdfare the adjustments for ESR (R) measurement when the Q of the capacitor is taken into account.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 26, 2022, 09:27:11 pm
content: Quote from: mawyatt on July 26, 2022, 09:03:56 pmThe IM3570 only costs $5000 more.Have a look at this thread of mine from a while ago when the IM3570 was new to me. I should have titled it "Fun with a Hioki IM3570".https://www.eevblog.com/forum/projects/capacitor-measurements-on-an-impedance-analyzer/msg178362/#msg178362

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 26, 2022, 09:31:12 pm
content: Quote from: mawyatt on July 26, 2022, 09:03:56 pmI think the manufacturers of the polystyrene film decided it wasn't worth it to keep manufacturing. I remember when the only manufacturer of polycarbonate film also decided to get out of that business. I still have an assortment of stacked film polycarbonate caps made by Siemens that the rep gave me years ago. Those were good caps for their time with respect to ripple current capability.

author: Martin72
author_rank: Super Contributor
timestamp: July 26, 2022, 09:54:49 pm
content: Well...QuoteHigh quality equipment has its justification, to say the least.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 26, 2022, 10:37:16 pm
content: Here is an example of how extremely low loss capacitors can overwhelm even the best LCR meters. On eBay are offers for very high performance capacitors from Ukraine left over from the USSR military. I bought some of them and this is a .5 uF polystyrene capacitor. One half microfarad is rather large for a polystyrene capacitor. Here is what the Hioki IM3570 gets for a measurement at 10 Hz:At first glance it looks like the measurements of a very low loss cap. But, wait a minute! The ESR is negative!! The D value is negative!? The IM3570 just can't do it! And, even though the D is negative, look at its value: .000017. WOW!!This is a situation like TimFox described where the only hope of getting a value is with calorimetry.

author: mawyatt
author_rank: Super Contributor
timestamp: July 26, 2022, 10:45:34 pm
content: Your frequency is only 10Hz, try a higher frequency.Best,

author: Martin72
author_rank: Super Contributor
timestamp: July 26, 2022, 10:52:38 pm
content: Oh, indeed.Nanofarad and some Hertz...won´t fit.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 26, 2022, 11:01:44 pm
content: Quote from: mawyatt on July 26, 2022, 10:45:34 pmAs I said in the sentence just before the image, the measurement is at 10 Hz. I showed that because that's the frequency where the IM3570 got negative values for ESR and D.Here are the measurements at 1 kHz and 10 kHz. This is the highest Q capacitor I have:

author: TimFox
author_rank: Super Contributor
timestamp: July 26, 2022, 11:05:53 pm
content: Regardless of whether data sheets have been written carefully, it's important to note the complex (mathematically) nature of the impedance of a capacitor-looking component.Since there is a small (hopefully) but finite coupling (or leakage) between the in-phase (real) and quadrature (imaginary) components in a real machine, the capacitance and ESR of a high-Qcomponent are going to affect each other, specifically the displayed (small) resistance will suffer a small effect from the (larger) measured reactance, which in turn is inversely proportional to the displayed capacitance.A practicable specification for a physically realizable meter (not a legal fiction) is the maximum resolvableQfactor (or minimumD), or the maximumQfor a given accuracy of the displayedQ.Too many people look at a data sheet and assume that the component can meet any combination of the line items simultaneously, without reading or understanding the relationships (e.g., maximum voltage, maximum current, and maximum power that cannot be safely applied simultaneously.)The negativeDvalue reminds me of my missed Nobel prize when I measured a negative noise factor on a very-low-noise RF amplifier due to a slight miscalibration of the apparatus.

author: mawyatt
author_rank: Super Contributor
timestamp: July 27, 2022, 12:27:06 am
content: Getting negative values for ESR and D is not difficult, we just did so with a 10nF Polystyrene at 10, 100 and 1KHz.If you look at the impedance angle, the phase drops slightly below -90.0 degrees which is obviously impossible for a real capacitor with a simple series C and ESR model. So this is just dancing around the limits of measurement for a particular instrument and DUT, where a higher measurement frequency increases the DUT current and lowers the instrument transimpedance gain (lower feedback resistor that senses the DUT current) moving back into a region where the instrument can provide a meaningful measurement, and why we mentioned such.Best,

author: mawyatt
author_rank: Super Contributor
timestamp: July 27, 2022, 12:51:15 am
content: Quote from: TimFox on July 26, 2022, 11:05:53 pmReminds me of a couple physicist searching for the magnetic monopole long ago. They sent up a detector in a balloon and when developing the photographic plates from the detector found a trace and claimed it was the elusive magnetic monopole. They also missed the Nobel when later it was discovered the plate was installed 90 degrees out of phase...oopsOn a closer note, we had a similar case when IBM provided a new HICUM SiGe bipolar model, under certain conditions this model would negate some of the noise from the driving source. They didn't win a Noble either, more like a pie in the face when we notified them about the magic transistor!!Best,

author: indman
author_rank: Super Contributor
timestamp: July 27, 2022, 09:15:35 am
content: Quote from: The Electrician on July 26, 2022, 09:01:40 pmI've read this guide before and it introduces even more questions than answers!"Secondary Parameters Accuracy:Az = impedance (Z) accuracyDefinition: Q = 1/D & Rp = ESR * (1+1/D2)D value accuracy: Dz = ± Az *(1+D)ESR accuracy: Rz= ± Zm * Az (Ω)ie., Zm = impedance calculated by 1÷(2πƒC) or 2πƒLPhase angle Θ accuracy: Θz= ±(180/ππππ)*Az (deg)"What should I understand from this? What is Az - an unknown impedance value, which, under the condition D<0.1, is characterized by the reactance of the capacitor? In what units is it calculated? And how does this explain the "fantastic" results secondary parameters when measuring high-quality polypropylene capacitors? Why does the manual not specify the accuracy and tolerance in % as it is done for the primary parameters L-C-R?It turns out that I myself have to conduct experiments and determine the degree of reliability of the testimony?Or does the device manufacturer have to do it?And if I don't have a "TH/ST" class device to compare readings with?

author: Martin72
author_rank: Super Contributor
timestamp: July 27, 2022, 10:49:39 pm
content: QuoteEven when you got one, it won´t bring you any further as they also can´t measure/displaying it correctly.Example, mentioned before, the 10nF mica cap I´ve measured it with the ET4410, the U1733C from keysight and the ST2830 from sourcetronic.All meters measured the capacity correctly inbetween their accuracies and inbetween the tolerance of the cap.All meters measured the Xc correctly.But none measured theexpectedESR correctly.Expected means in this case the calculated one, based on the values of the Tan phi from the spec.It should be in the range of appx 16ohms at 1khz.The ET4410 displays appx 5 ohms, the ST2830 appx 3 Ohms and the keysight "freaks out", displaying something and blinking all the time.The most probably reasons why you´ll find it here in this thread.So for me there are several conclusions "avaible".1.) Can´t expect to have it all even when you spend 1000 bucks or more for a LCR.2.) The "secondary" measure functions of the "cheapos" (including the 1000 bucks or more) like D or ESR are (probably, will test it soon) trustable for caps with "bad" losses like electrolytic ones.3.) When you wil get in a situation (as a hobbyist) to know exactly the losses/ESR of a high Q cap? Isn´t it more practical to know the ESR of a electrolytic cap which the meters could display trustable?4.) Developers choosing a cap for their circuit design according to the specs of the manufacturer, not by measuring it before.The only exception is to know the exact capacity (for filters) - And capacity every not too cheap meter can measure it correctly.So why we private ones will go further...Buy a cap from a known manufacturer according to the specs it got and you need and that´s it.5.) Knowing the exact ESR is in the most cases interesting by electrolytic caps (switching power supplies) when you must repair something. And the ESR of these ones even a cheaper meter should measure it.

author: indman
author_rank: Super Contributor
timestamp: July 28, 2022, 07:00:35 am
content: Quote from: Martin72 on July 27, 2022, 10:49:39 pmI agree with this 100%! This information should have been placed in the documentation for the device, and not to invent fantastic formulas with unknown variables that confuse the user even more.If we follow your logic, then the measurement of secondary parameters for high-quality non-electrolytic capacitors for devices of this class is NOT RELIABLE and is only for evaluation and familiarization purposes,what does the status of an amateur meter mean!For me, this conclusion is obvious and so far no one has convinced me otherwise.Quote from: The Electrician on July 26, 2022, 10:37:16 pmName the marking of this capacitor or show a photo of it, if possible. I'll look for the same one in my stocks..

author: mawyatt
author_rank: Super Contributor
timestamp: July 28, 2022, 12:49:53 pm
content: Any quality somewhat larger value Polystyrene cap should suffice for experimenting and duplicating the high "Q" issue with ESR.Here's an surplus example from TRW:https://www.surplussales.com/Capacitors/Poly-Unelco.htmlBest,

author: indman
author_rank: Super Contributor
timestamp: July 28, 2022, 01:00:27 pm
content: mawyatt,it's not a secret to me. I wanted to find out the marking of the capacitor that measuredThe Electrician

author: Martin72
author_rank: Super Contributor
timestamp: July 29, 2022, 08:46:22 pm
content: Quote from: Martin72 on July 25, 2022, 08:48:49 pmToday a electrolytic cap on my ET4410, same cap then on monday with the lcrs on work.It´s a low esr type from panasonic, 100µF/35V.Results with 120hz, 1Vrms, series:C: 102.96µFXc : -12.882 OhmD: 0.0208Q: 47.388Phase: -88.79°ESR: 0.2699 Ohm (stable..)So far, so good, everything seems plausible, you can take the values and calculate, everything is coherant.But I´ve choose this type of cap, because a spec sheet is avaible.And the sheet "says" at 120Hz the D-factor will be 0.12 for the 35V type....Of course there are tolerances, but appx 6-times less..I trust the value in the spec more than the measure.Taking the D-factor from the spec, taking 100µF, calculations are Xc -13.26 Ohm, Q 8.33, ESR appx 1.59 OhmThe measured Xc seems plausible, so why are D and Q so different..I think it got to do with the here already mentioned signal to noise ratio.Actually I read the very good keysight handbook, makes things clearer for me - Thanks for the hint !

author: TimFox
author_rank: Super Contributor
timestamp: July 29, 2022, 08:49:56 pm
content: Normally, the specifiedDvalue on a data sheet is amaximum, not a "bogie" value. Was there a percent tolerance indicated on the data sheet?I would look it up myself, but you didn't state a Panasonic part number.

author: Martin72
author_rank: Super Contributor
timestamp: July 29, 2022, 09:05:44 pm
content: As far as I can see not for the tan-phi.But maybe you see more:https://cdn-reichelt.de/documents/datenblatt/B300/EEUFR_ENG_TDS.pdfA few minutes ago I doubled the output voltage to 2Vrms, no effect.Same when using the mode with 1.5V bias.

author: TimFox
author_rank: Super Contributor
timestamp: July 29, 2022, 09:48:45 pm
content: On that data sheet, there is a specified tolerance for the capacitance value (+/- 20% when measured at 120 Hz), but no tolerance on the tan delta (D) value.They do not control the actual value ofD, which is not practicable, but they test formaximumD.This is normal for a capacitor data sheet.

author: TimFox
author_rank: Super Contributor
timestamp: July 29, 2022, 10:26:49 pm
content: If you are trying to test your meter, you might do the following:The largest polypropylene capacitor in my hobby inventory is 20 uF.Larger ones are available. 100 uF/400 V from Wima costs about $22.00 in singles, and is specified at only 10 kHz (due to its use in switching devices).The 20 uF capacitor, measured at 120 Hz on my trusty DE-5000 reads "OL" onQ.Assuming Q > 1000, the ESR < 0.066 ohms.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.

author: Martin72
author_rank: Super Contributor
timestamp: July 29, 2022, 11:30:40 pm
content: Hi Tim,Good advice, got several caps here at home with several materials build up, let´s see.QuoteExactly this is the point.When you don´t know the manufacturer, there´s no sheet avaible, you must trust your meter.What the main parameters concerns I have no doubt about it.In case of the DE5000 you shouldn´t have no doubt about it too, I´ve tested it so much in comparison to official calibrated ones, when you "only" want to know the LCR values, its more than enough with the DE5000.But sometimes I need to know at least one of the "secondary" parameters and it would be good when you can trust your meter.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 30, 2022, 12:55:06 am
content: Quote from: indman on July 28, 2022, 07:00:35 amThey look this:https://www.ebay.com/itm/193196126203?hash=item2cfb62effb:g:FLgAAOSwZL5dwu1nbut mine are .5 uFI also have some like this:https://www.ebay.com/itm/203495673318?hash=item2f61498de6:g:MFoAAOSwXtFiNb1gNotice that both of these sellers are in Ukraine.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 30, 2022, 02:11:07 am
content: Quote from: Martin72 on July 29, 2022, 11:30:40 pmFor some reason the data sheet you found for the Panasonic cap has deviated from the industry standard. Data sheets for small electrolytics nearly always specify that the given value of D is "max".Have a look at any of these data sheets:https://www.rubycon.co.jp/en/products/al-radial-lead/series/You should be able to trust your meter for electrolytics because their D won't ever get close to .001. The one thing that leads to the DE5000's inability to get a good measurement at frequencies above 100/120 Hz is that the electrolytic is large value. For example, when I try to measure a 33000 uF cap, I get OL on every frequency except 100/120 Hz.

author: Martin72
author_rank: Super Contributor
timestamp: July 30, 2022, 01:57:22 pm
content: QuoteTested 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).

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 30, 2022, 07:51:42 pm
content: Quote from: indman on July 27, 2022, 09:15:35 amAz 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.pdfThis 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?

author: TimFox
author_rank: Super Contributor
timestamp: July 30, 2022, 08:22:14 pm
content: 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.

author: Martin72
author_rank: Super Contributor
timestamp: July 30, 2022, 08:46:44 pm
content: QuoteDoesn´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.

author: TimFox
author_rank: Super Contributor
timestamp: July 30, 2022, 09:11:56 pm
content: You cheated by reading the datasheet.It's like affecting a physical situation by doing a measurement.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 30, 2022, 09:19:08 pm
content: Quote from: TimFox on July 30, 2022, 08:22:14 pmThe best that can be done with these handheld meters is to use the built-in four blade fixture. The point of my post was to show that there are other handhelds that can do much better than the DE5000 under certain conditions. The measurements the Tonghui and Applent got were within a few percent of the Hioki's result, unlike the DE5000's result. But, of course they cost several times what the DE5000 cost.100 kHz isn't such a high frequency for this measurement.

author: Martin72
author_rank: Super Contributor
timestamp: July 30, 2022, 09:39:29 pm
content: Quote from: TimFox on July 30, 2022, 09:11:56 pmMe ?Please explain why.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 30, 2022, 09:44:18 pm
content: Quote from: Martin72 on July 30, 2022, 08:46:44 pmI wasn't expecting the DE5000 to get a good value for the capacitance. I only mentioned what the DE5000 got for the capacitance of the 1800 uF cap (which was OL) to compare it to what other meters get. The other meters got a negative value which shows that 100 kHz is above the self resonant frequency; but they didn't just give up and say OL.What I want an LCR meter to do is be able to measure the ESR of a large capacitance at 100 kHz. This shouldn't be a difficult measurement due to a low value of D (high Q). Switching the DE5000 from capacitance measuring mode to the Rs measuring mode at least gives a value which is substantially in error.Another thread from some time ago did some tests that showed that the DE5000 has difficulty making measurements when the voltage across the DUT is about 4 millivolts or less, which can be the case when measuring capacitors of this size capacitance. That appears to be the case here. But the Tonghui and Applent don't have that limitation.

author: Martin72
author_rank: Super Contributor
timestamp: July 30, 2022, 10:57:04 pm
content: QuoteHmm..What will be "better", don´t "giving up" and display anything or show clearly it´s not the range I can measure something like this...The smart way would be to "obey" frequencies above(E.g., at 2000µF range testfrequencies up to 1khz max are possible), but this would require a manual mode which the DE5000 and many others don´t got.

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 30, 2022, 11:26:55 pm
content: Quote from: Martin72 on July 30, 2022, 10:57:04 pm

author: TimFox
author_rank: Super Contributor
timestamp: July 31, 2022, 02:48:34 am
content: Quote from: The Electrician on July 30, 2022, 09:44:18 pmMeasuring the ESR of a large capacitance with a high Q (low D) is, in fact, avery difficultmeasurement. [Emphasis added inbold faceabove to original comment.]

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 31, 2022, 03:28:13 am
content: Quote from: TimFox on July 31, 2022, 02:48:34 amI worded what I was saying in an ambiguous way. Let me rephrase it; replace that sentence with this one:"Since in this case (of a large electrolytic) we won't have a low value of D (high Q), this shouldn't be a difficult measurement."

author: mawyatt
author_rank: Super Contributor
timestamp: July 31, 2022, 01:07:46 pm
content: One should have a good handle on how these LCR meters work and the ranges that are within "acceptable" limits of such. Some of the higher end LCR meters display (selective) DUT current and applied voltage, these parameters are beneficial to access the viability of the DUT measurement.One should also consider the impedance magnitude involved, a few milliohms will be difficult to accurately measure and requires a large measuring DUT current which a handheld battery powered device may have difficulty supplying.If you consider an ideal 1000uF produces just 0.0016 ohms at 100KHz, with a DUT current of 0.1 amp this only produces 160uV across the DUT. However, a more practical measurement at 100Hz produces 1.6 ohms and 160mV across the DUT at 0.1 amp.The DE-5000 we have produces just ~5ma maximum available current which limits the ability to sense low impedance magnitudes, the better LCR meters produce much more available current for measurements.Best,

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 31, 2022, 04:21:39 pm
content: Quote from: mawyatt on July 31, 2022, 01:07:46 pmThe first thing I said in reply #20, my first post in this thread was: "Your problem is undoubtedly a matter of signal to noise ratio."I've been harping on this for the rest of my posts, and it's good to have some older, experienced EEs confirm.It hasn't been mentioned yet, but one of the limitations of the fact that the DE5000 has integrated the entire functionality of an LCR meter is that compromises were necessary. The IC process they had to use was not the best suited for low noise performance. A meter not fully integrated can use a low noise opamp, or even a fully discrete design, for the front end gain stage.The marketing literature for the Hioki top end meters, and the Keysight E4980A meter, describe how their engineering teams expended considerable effort to reduce the front end noise. Here's some of the Keysight description of how the noise reduction affects low impedance measurements:

author: mawyatt
author_rank: Super Contributor
timestamp: July 31, 2022, 05:12:12 pm
content: Quote from: The Electrician on July 31, 2022, 04:21:39 pmNo doubt the chip set utilized within the DE-5000 is CMOS since it must support significant digital as well as the analog front end. Enormous strides in CMOS noise levels have been achieved over the decades including some clever signal processing to "help" with the noise. Apparently the chip set utilized is two separate chips, suspect one is analog and other is digital and they may not be produced in the same CMOS process. From experience I can tell you this is no trivial feat to implement an entire LCR meter within a couple chips, even if only modest performance....so hats off to the chip set designers!If you check the latest CMOS Op-Amps from TI and AD you'll find some pretty good noise performers, even tho they are CMOS. This is a result of superb design, clever techniques and a good CMOS noise friendly process that's likely proprietary and not really available to the outside. Of course there are excellent bipolar Op-Amps available also, so a LCR design team would have the luxury of selecting the best Op-Amps for noise performance, the best SD ADC, the best DDS and so on, whereas the custom IC LCR designers were quite restricted and thus performance is compromised.One area that might be beneficial to the custom chip set LCR meter types, where one could significantly "Boost" the output current for lower level impedances, which as you correctly indicate would improve the SNR. A high speed/current discrete buffer amp or something like a OPA-633 could extend the range of the chip set significantly, but you would still want this in a mains powered LCR meter, not a handheld battery powered since the power consumption would be high (why our Hioki has a very loud fan, the TH2830 fan is not as bad tho, but it only goes to 100KHz).Anyway, that's a nice document from KS, thanks for showing!!Best,

author: TimFox
author_rank: Super Contributor
timestamp: July 31, 2022, 06:27:56 pm
content: In the G-R "Digibridges", the analog circuitry was separate from the computation circuitry, which allowed higher currents and lower noise voltage.The G-R/Quadtech 1659 uses an NE5534 op amp with a high-current buffer to drive the "low" terminal with the high current required from a powerful source through the DUT.This allows measuring high current at virtual ground (0 V).An earlier version in my inventory of not-yet-repaired units used a CA3130 CMOS op amp with multiple CMOS inverters to buffer the output, if I remember correctly.

author: Martin72
author_rank: Super Contributor
timestamp: July 31, 2022, 06:42:04 pm
content: ET4410:The signal output stage to H-Cur got a push-pull stage, the output resistance is switchable from 100Ohms to 30Ohms, maximum output voltage is 2Vrms.Pic shows the actual state of my attempt to draw the circuit, according to the keysight handbook, it´s a auto-balancing bridge.

author: mawyatt
author_rank: Super Contributor
timestamp: July 31, 2022, 07:07:36 pm
content: The "low" terminal should be a transimpedance amplifier with a selectable feedback resistor to "force" the low side to ~ 0 volts. At very low impedances the DUT current may reach ~0.1 amp in lab type LCR meters and the transimpedance amp must sink/source this at 0 volts and use as low as 10 ohm feedback resistor. This is likely a buffered Op-Amp type transimpedance amp. The "high" side is likely driven by another buffered op-amp with a selectable output resistance as low as 30 ohm to drive the DUT.Both the transimpedance amp output and the DUT voltage are sensed with a synchronous technique which imposes a narrow bandpass filter around the injected signal which dramatically improves noise, interference rejection and sensitivity, a tried and true technique employed for well over half a century.Best,

author: Martin72
author_rank: Super Contributor
timestamp: July 31, 2022, 07:49:18 pm
content: Yepp,Not so bad for a cheap one.Test a panasonic FM electrolyt cap, 1000µF/25V on 100khz a few minutes ago.ESR 0.034 OhmD 0.128Xc -0.267 OhmQ 7.81Phase - 82.7°And cap....5.95µF

author: TimFox
author_rank: Super Contributor
timestamp: July 31, 2022, 08:00:31 pm
content: Quickly approaching self-resonance at that frequency...

author: mawyatt
author_rank: Super Contributor
timestamp: July 31, 2022, 09:10:07 pm
content: Quote from: Martin72 on July 31, 2022, 06:42:04 pmIf you trace the Low Cur terminal on the PCB, you'll probably find another Buffered type amplifier with all the selectable resistors shown or the right. With a 30 ohm output and 2 volt signal the max DUT current is 67ma, that's a lot of current for a small Op-Amp to handle without some aid!!Best,

author: Martin72
author_rank: Super Contributor
timestamp: July 31, 2022, 09:43:13 pm
content: Actually can´t find it in the manual, but there is a "overload" warning I´ve already reached sometimes..

author: mawyatt
author_rank: Super Contributor
timestamp: July 31, 2022, 10:14:32 pm
content: Noted a few things in the schematic you've shown. First off there is a simple technique we've used for decades to "assist" with cross-over distortion in buffered outputs. The 200 ohm resistor R210 from the op-amp output to the buffered output serves to supply current during the cross-over around the zero point where the Slew Rate is the highest and the buffer devices may have trouble keeping up since they are lightly biased there. As the signal increases the Slew Rate slows some and output transistors begin to take the current load away from the op-amp and after 4~5ma the op-amp maxes out. If implemented properly this works very well.Another couple points, it appears the meter is utilizing the +-5V supply as somewhat references since the signal waveform seems to be coming from the controller and would be a 0 to 5V pulse train to create the signal sine wave and the multipole filter is to filter out everything and leave a nice clean sine wave. The result from the filter will be a unipolar sine wave and this is offset to swing about zero by using the -5V and a resistor R215 (also R205) into the summing node op amp configuration. Using the controller to create a PWM pulse train eliminates the need for a sine wave generator DDS & DAC. Nothing wrong with this approach as it saves some $ in the BOM, but doesn't possess the precision of a typical lab type instrument, but doesn't cost as much either, so very cost effective!! Think todays linear regulator chips are much more stable than those from long ago, know the ones we've utilized were pretty stable and almost spot on the desired output voltage.Best,

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 31, 2022, 10:25:52 pm
content: Quote from: Martin72 on July 31, 2022, 07:49:18 pmWhich meter did you use to make this measurement? Something's wrong with these numbers. The phase can't be anywhere near -90 degrees for a 1000uF electrolytic at 100 kHz. Would you please do this over. Also show the numbers at 100 Hz for comparison, and measure a few caps larger than 1000uF at 100 kHz please.

author: mawyatt
author_rank: Super Contributor
timestamp: July 31, 2022, 10:32:49 pm
content: Quote from: Martin72 on July 31, 2022, 09:43:13 pmNow get yourself a DIY DC Bias Fixture and see just how bad some of the ceramic caps vary with DC bias, also check out the Mylar film types, and electrolytic, then you're nice Mica and Polystyrene types!! Then try some semiconductor diodes to see how they behave with DC bias, fun stuff indeed!!Oh, and don't forget the DIY Isolation Transformer for Bode Plots of Open Loop parameters with your superb SDS HD DSOEdit: And forgot, put that nice Twin T notch Filter that you have in the feedback loop of an op-amp, makes nice narrow bandpass filter. Get a high Q inductor and measure it along with your high Q Mica caps, then create a Peltz oscillator!! Fun stuff aheadBest,

author: The Electrician
author_rank: Frequent Contributor
timestamp: July 31, 2022, 11:10:40 pm
content: Here are a couple of plots vs frequency of parameters of a 1000uF 16v Rubycon capacitor. The first plot shows the impedance magnitude |Z| (green) and ESR (yellow) over a frequency range of 100 Hz to 5 Mhz. You can see that starting at the left at 100 Hz, |Z| decreases with increasing frequency as we would expect for a capacitor, but somewhere before 100 kHz where marker B is, |Z| begins to increase. A |Z| that increases with frequency is behavior that we would expect from an inductor, and that increase is due to the ESL (equivalent series inductance) of the capacitor. The capacitance of the capacitor resonates with the ESL of the capacitor just below (it's at marker A in the second image) the frequency where marker B is; this is called the self resonance frequency of the capacitor.At frequencies above the SRF (self resonance frequency), an LCR meter which is set to measure capacitance will show a reading which is negative, because above the SRF the impedance of the capacitor is inductive.The second plot shows the same yellow curve of the ESR vs frequency, but now the green curve is the phase angle of the impedance of the capacitor being measured. The scale of the linear display is -90 degrees at the bottom, +90 degrees at the top. The green curve starts at the left (100 Hz) near the bottom, so at low frequencies the phase of the capacitor's impedance is nearly -90 degrees. As the frequency increases, the phase moves upward (but is still negative--capacitive in other words) until at marker A (65.027 kHz), the phase has reached zero degrees--the impedance is purely resistive. Continuing up in frequency, the phase angle continues to increase toward +90 degrees, staying positive, which means it's inductive.Notice the behavior near 100 kHz; the phase is close to zero degrees, and it can't be -82.7 degrees.

author: mawyatt
author_rank: Super Contributor
timestamp: August 01, 2022, 01:53:36 am
content: Nice plotsBest

author: Martin72
author_rank: Super Contributor
timestamp: August 01, 2022, 08:28:31 pm
content: Quote from: Martin72 on July 29, 2022, 08:46:22 pmResults keysight U1733C:103.65µFD: 0.018Q: 59.1Phase: 89.0°ESR: 0.273 OhmXc: forgottenResults ST2830:103.30µFD: 0.0198Q: 50.47Phase: 88.86°ESR: 0.255 OhmXc: forgottenI would say, all three LCRs are close together.The panasonic 1000µF cap on 100khz:Keysight : OLST2830: -32.57µF, 0.0154 Ohm (ESR), Q 3.16, D 0.317, forgotten the phase (tomorrow)

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 01, 2022, 09:55:36 pm
content: Quote from: Martin72 on July 31, 2022, 07:49:18 pmThis is the set of measurements from reply #103 that I think are not right. In reply #112 today you gave some numbers that are from a Panasonic 1000 uF cap."The panasonic 1000µF cap on 100khz:Keysight : OLST2830: -32.57µF, 0.0154 Ohm (ESR), Q 3.16, D 0.317, forgotten the phase (tomorrow)"Is this the same cap as in the quote above? These numbers are quite different. What meter did you use to make the original measurements in the quote from reply #103? Can you make measurements of the LCR meters at work of this Panasonic 1000 uF cap?

author: Martin72
author_rank: Super Contributor
timestamp: August 01, 2022, 10:24:59 pm
content: Hi,First measurements were taken at home on the ET4410, the last posted were at work on calibrated LCRs like keysight U1733C and Sourcetronic ST2830.Same caps used like home, the 100 and 1000µF from panasonic.Forgot the Xc parameter, so repeat it in the next days.

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 01, 2022, 11:10:08 pm
content: There's something odd about that Panasonic 1000 uF cap. Besides making the measurement on all the meters you have access to at 100 kHz, would you please make a measurement at 100 Hz, 1 kHz, and 10 kHz on the best meter.Edit: Another thing you might do is find some other 1000 uF electrolytic capacitors and make a few measurements at 100 kHz, to see if they are much different then the Panasonic one.

author: mawyatt
author_rank: Super Contributor
timestamp: August 01, 2022, 11:48:43 pm
content: "The panasonic 1000µF cap on 100khz:Keysight : OLST2830: -32.57µF, 0.0154 Ohm (ESR), Q 3.16, D 0.317, forgotten the phase (tomorrow)"Does the negative capacitance reading at 100KHz of the 1000uF Panasonic indicate an inductive reactance due to ESL, which would be past the series resonate frequency? If so, then the phase should be positive.Best,

author: mawyatt
author_rank: Super Contributor
timestamp: August 01, 2022, 11:58:40 pm
content: Quote from: Martin72 on August 01, 2022, 08:28:31 pmShouldn't this 100uF cap measured at 120Hz have a negative phase?Best,

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 02, 2022, 12:11:29 am
content: Quote from: mawyatt on August 01, 2022, 11:48:43 pmThere a number of things that make me think something's wrong, either with the capacitor itself, or the measurement.The plot of the impedance phase of a 1000 uF cap in reply #110 was intended to show that the self resonance of the typical 1000 uF electrolytic is near 100 kHz, and the phase is near zero degrees. I don't think it can be vary much from zero, plus or minus.The measurements in reply #103 gave this for the phase: "Phase - 82.7°". Is that a minus sign or is it a hyphen? Whichever it is, I don't think the magnitude of the angle can be as great as 82.7 Also the Q is given as 7.81 (the measurement reported today gives it as 3.16); I measured several 1000 uF electrolytic caps, and I can't find any with Q that high.Would you measure a few 1000 uF electrolytics and see what you get for Q at 100 kHz?

author: mawyatt
author_rank: Super Contributor
timestamp: August 02, 2022, 02:12:04 am
content: Quote from: The Electrician on August 02, 2022, 12:11:29 amThe only 1000uF electrolytic cap we have is an inexpensive Beryl 1000uF @ 16V RC(M) 2110 105C type.https://datasheet.lcsc.com/lcsc/1912111437_BERYL-Electronic-Tech-RC016M102LO10-16TH-2A1E_C357639.pdfMeasured with Tonghui TH2830, Hioki IM3536 and DE5000. Very quickly done without calibration or a proper warmup.TH2830 100Hz 1KHz 10KHz 100KHzC 913uF 874uF 1,117uF -105uFESR 0.109 0.051 0.048 0.057Angle -86 -74 -16 +15D 0.06 0.28 3.55 3.80IM3536C 911uF 878uF 1,243uF -66uFESR 0.120 0.056 0.053 0.063Angle -86 -73 -14 +21D 0.07 0.31 4.14 2.56DE5000C 923uF 875uF OL -101uF (computed from Ls)ESR 0 0.04 0.04 (Rs)Angle -87 -77 +19D 0.06 0.23 2.89Appears the SRF is ~24KHz (Z magnitude angle ~0). Note the 100KHz measurement with DE5000 was with Ls and Rs, C computed from ~ 1/[(2*pi*100KHz)^2 * Ls]Anyway, this seems like a typical low end cap, not sure about the Panasonic Martin measured tho, maybe a special Polymer type or something?Best,

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 02, 2022, 07:14:51 am
content: Martin72, do you have a link to a spec sheet for the Panasonic 1000 uF cap you measured in reply #103?If not, do you know if it's a polymer capacitor, or some other type that would be exceptionally low loss?

author: MegaVolt
author_rank: Frequent Contributor
timestamp: August 02, 2022, 08:26:04 am
content: Quote from: The Electrician on July 31, 2022, 11:10:40 pmWith what device these wonderful graphs were taken?

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 02, 2022, 12:34:00 pm
content: This:https://www.hioki.com/us-en/products/lcr-meters/3-ghz/id_5772Also Google this: IM3570E14-23M.pdf

author: mawyatt
author_rank: Super Contributor
timestamp: August 02, 2022, 06:24:37 pm
content: For those of us without a nice Hioki IM3570 we can generate some decent plots of DUT Capacitance Impedance Magnitude and Phase with a scope and signal generator. Simply sweeping the source frequency over the desired range and measuring the amplitude and phase of the voltage across across the DUT and current thru the can yield the result with a little math.Z = V/I (Magnitude and Phase), where V is voltage across the DUT and I is the current thru the DUT which can be measured by inserting a known resistor R in the signal path to the DUT. Then the DUT current is Voltage across the resistor divided by R.If you have a modern DSO like the Siglent SDS2104X+ which has a built-in Bode function you can employ this to make the nice plots directly on the screen in dB magnitude and phase of Cap DUT Z vs. frequency.If folks are interested we could start another thread on this technique, so as not to dilute this thread.Anyway, here's a plot of a 1000uF 16V electrolytic capacitor, another 10uF, 680uF and 100uF. The scale is in dB 1000 ohms and phase is in degrees.Best,

author: Martin72
author_rank: Super Contributor
timestamp: August 02, 2022, 08:11:20 pm
content: So...Today I´ve measured the both panasonic caps at work again, the menu of the ST2830 is not the clearest one.A few minutes ago I did the same again at home on the ET4410, to have it all in one post.The 100µ cap at 120Hz:ST2830 ET4410103.16µF 103.33µFXc -12.86 Ohm -12.84 OhmQ 51.10 51.80D 0.0196 0.0192ESR 0.252 Ohm 0.250 OhmPhase -88.88° -88.89°At 100Khz:26.50µF 15.40µF-0.071 Ohm -0.104 Ohm1.607 2.4270.6185 0.41150.038 Ohm 0.043 Ohm-57.86° -67.63°1000µF at 120HzST2830 ET4410945.91µF 946.8µFXc -1.402 Ohm -1.401 OhmQ 28.60 29.04D 0.035 0.035ESR 0.049 Ohm 0.048 OhmPhase -87.99° -88.03°At 100Khz72.50µF 23.80µF-0.025 Ohm -0.067 Ohm1.578 3.7560.632 0.2660.014 Ohm 0.018 Ohm-57.31° -75.20°At 120Hz they are like twins..Datasheets:1000µF/25V FM Type:https://www.micro-semiconductor.com/datasheet/37-EEU-FM1E331LB.pdf100µF/35V FR Type:https://industrial.panasonic.com/cdbs/www-data/pdf/RDF0000/ABA0000C1259.pdf

author: TimFox
author_rank: Super Contributor
timestamp: August 02, 2022, 09:15:55 pm
content: Since you are approaching self-resonance at 100 kHz, the measured reactance/capacitance will depend on the lead length in your fixture.It only takes 2.5 nH to resonate 1000 uF at 100 kHz.

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 03, 2022, 12:12:16 am
content: Quote from: mawyatt on August 02, 2022, 06:24:37 pmHere as some plots done on the IM3570, with colors set to match yours.One thing that your plots aren't getting right at the extreme frequencies. The phase curve vs frequency should be monotonic.The first one is of a 1000 uF cap of moderate loss:Here is a plot of another 1000 uF cap with lower loss. You can see the effect of lower loss; the curvature of the bottom of the |Z| curve is more rapid the lower the loss:Here are both plots superimposed:

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 03, 2022, 12:28:03 am
content: Quote from: Martin72 on August 02, 2022, 08:11:20 pmMartin72,Would you please post a photograph of the fixturing or Kelvin cable you are using to make measurements of your ET4410 and the meter at work?

author: mawyatt
author_rank: Super Contributor
timestamp: August 03, 2022, 12:40:41 am
content: Quote from: The Electrician on August 03, 2022, 12:12:16 amThat's due to the setup fixturing or lack thereof, just a Proto-Board, Scope Probes, 1K 2W leaded resistor and 1 Meter BNC to Clip lead cable, unterminated. No attempt was made to keep things short and proper for RF type frequencies, just a quick test to show how the DSO can implement a nice Impedance Plot with the help of the Bode Function. Also didn't change the scope input channels to 200MHz or full BW from 20MHz BW which probably should have done. Also should add, that the DUT "sees" the source 1K Resistor which affects the low frequency response.Best,

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 03, 2022, 01:16:51 am
content: I figured there were reasons, related to the likelihood that you hadn't made a major project out of it!

author: mawyatt
author_rank: Super Contributor
timestamp: August 03, 2022, 12:47:04 pm
content: Yep, just a quick setup and test. Here's couple of plots for a 100uF and 10uF Polymer types, they agree with TH2830 as 95.19 (97.73uF) @ 100Hz and 9.16 (9.76uF) at 1KHz. Note these plots only go to 1MHz to stay within reason for the kludge setup involved.If Siglent is "listening", this has demonstrated that the SDSX + and even better SDSX HD are capable of generating useful Impedance Plots. If they had the ability to plot a Resistance scaled Y axis then the display would be in dB ohms, and with the ability to do a short open calibration and utilize such in the display. Add to this the ability to "plot" various computed parameters (C, Z, Y, D, Q, ESR) within the Bode Function, well you see where we are goingWith this we could add a quality test fixture with selectable ranges (we know how to do this!!) and you now have a wideband Impedance Analyzer of decent performanceMaybe Siglent is listeningBest,

author: Martin72
author_rank: Super Contributor
timestamp: August 03, 2022, 08:45:03 pm
content: Quote from: The Electrician on August 03, 2022, 12:28:03 amHi,Did it, the last measures were all taken with the kelvin cables.Then I remember I got the fixture also and repeated the 100Khz measure today at work and at home.Will do a little table with the results of yesterday and today, post it when finished.There are remarkable differences between fixture and cable.Martin

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 03, 2022, 09:07:05 pm
content: Quote from: Martin72 on August 03, 2022, 08:45:03 pmI had just about decided that your unusual measurements were due to using cables. Can you make measurements on the Panasonic 1000 uF cap at 120 Hz, 10 kHz and 100 kHz on both the ET4410 and at work on the ST, using the fixture?

author: Martin72
author_rank: Super Contributor
timestamp: August 03, 2022, 09:23:55 pm
content: Can do."Unsual"...I guess you mean the 100khz measures, at 120hz both measure the same.(For other readers who ecventually wondered why I use only the ET4410 and the ST2830, the keyysight handheld LCR, expensive and calibrated, measures on 100khz complete BS)

author: indman
author_rank: Super Contributor
timestamp: August 04, 2022, 05:44:31 pm
content: Quote from: The Electrician on July 30, 2022, 12:55:06 amThank you, these are very high quality styroflex (polystyrene) K71-7 capacitors. I keep them in a separate box, but I don't have the 0.5uF rating. I took a slightly lower value of 0.15uF for comparison and the results on the DE-5000 are very close to yours from post #68. I have shown in the screenshots the results of measurements using the software Hand-Held LCR for De-5000 at 1kHz and 10kHz. These pictures show that the DE-5000 can display more useful information than it has on the display and more high resolution for Q,D and other. ESR(Rs) at 1kHz is very unstable and fluctuates a lot, so I only showed 10 and 100kHz.Quote from: The Electrician on July 30, 2022, 07:51:42 pmEverything is relative in this world, right? For me, $100 is not such a small amount. I have a Chinese LCR XJW01 with a price of $30 and I would not say that it is 3 times worse than the DE-5000. I also have an LCR measuring attachment with a computer sound card, which in Zmeter can draw similar Bode graphs and almost for free. Yes, there is a limit on the upper limiting frequency of 10-20 kHz. Therefore, if I buy an ET4410, which is 3 times more expensive than a DE-5000, this again does not mean that I will have a meter 3 times better in quality.

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 06, 2022, 01:02:29 pm
content: Martin72, have you had a chance to make measurements of the Panasonic 1000 uF electrolytic? If so, please share your results with us.

author: Martin72
author_rank: Super Contributor
timestamp: August 06, 2022, 02:32:07 pm
content: Hi,Yes I had...Yesterday made measurements on the ST2830 at work and with the fixture, then the same at home with the ET4410.At 120Hz, 1Khz, 10Khz and 100Khz.Also the 100µF Panasonic.Values will come, probably in the next hours..

author: Martin72
author_rank: Super Contributor
timestamp: August 06, 2022, 05:03:18 pm
content: Table...Blue are the measures from the ET4410.All measures with the fixture, when I got time I´ll make another table with the measures taken from them with kelvin clips.Martin

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 06, 2022, 09:55:21 pm
content: Can the ST2830 set the frequency to frequencies other than the standard 100, 120, 1k, 10k and 100k?Can your ET4410 do frequencies other than the standard 100, 120, 1k, 10k and 100k?

author: mawyatt
author_rank: Super Contributor
timestamp: August 06, 2022, 10:07:24 pm
content: Martin has indicated that the ST2830 is a rebadged TH2830, and if so our TH2830 can be set to any frequency within 50Hz to 100KHz with sub Hz resolution at lower frequencies, and 1Hz resolution at 100KHz. So highly likely a DDS based signal source.Best,

author: Martin72
author_rank: Super Contributor
timestamp: August 06, 2022, 10:13:36 pm
content: @The Electrician:Yes and yes...ET4410 got 16(20 are mentioned in the spec) steps between 100Hz and 100khz.ST2830 got 34 steps between 50hz and 100Khz.What I´ve saw after buying the ET4410:ET4510 allows free choosable frequencies with 1Hz resolution..Here a snip from the manual, which frequency fits in the accuracy spec.@mawyatt:TH and ST are absolut the same and while I´ve searched the china stores for LCRs, some remarkable thing comes up.In several cases, when you buy more, you can give the LCR your own name...Edit: added ST2830 frequencies

author: mawyatt
author_rank: Super Contributor
timestamp: August 06, 2022, 11:01:04 pm
content: @Martin,Our TH2830 can be set to any frequency between 50Hz and 100KHz. Just connected the LCR probes to a counter and typed in 10.123KHz and got 10.122889KHz, then entered 51.987Hz and got 51.986334Hz, then entered 87.654KHz and got 87.653044KHz, 99.999KHz and got 99.997911KHz, then 99.999Hz and got 99.997995Hz. That's why I indicated this is using a DDS for the signal generation.This must be an "undocumented" feature, as you enter the desired frequency using the "inc" and "dec" keys you step thru the predefined frequencies as you expect from the spec sheet.However, if you use the keypad the screen will turn RED for the frequency display, even if you hit "Enter", but if you select Hz, KHz it accepts the input (as long as KHz is less than 100, and Hz is greater than 50), screen turns blue and the LCR meter outputs the desired frequencyIf you try MHz the meter beeps and displays a RED Out of Range Error message, same with above for <50Hz or >100KHz.So it seems that the TH2830 can implement just about any frequency between 50Hz and 100KHz even tho the specs indicate NOTI'll wager a brew that your ST2830 can do the same if you use the keypad technique described aboveKnow Thomas has a TH2830, hopefully he will spot this and give it a try!!!BTW, the DDS is likely be big cost saving difference between the ET4410 and the TH2830.Best,

author: Martin72
author_rank: Super Contributor
timestamp: August 06, 2022, 11:09:11 pm
content: Interesting, will try this on mondayBTW trying, It think I will test the pansonic caps on the scope like you did.

author: mawyatt
author_rank: Super Contributor
timestamp: August 06, 2022, 11:28:06 pm
content: Use the Diff Amp technique if you have one. TopQuark also has an HD and has produced some stunning plots of various capacitor parameters with his Python routine which collects data from the HD Bode Plot, does some calculations and creates the plots.Try and keep the setup tight for good results, we've run all sorts of caps from Electrolytics, Polymers, Mylar, Polypropylene, ceramic and even some inductors. The technique works well and is great for showing resonances and minimum impedances, much much better than a display number. Sure it's not as accurate as a proper LCR meter like your ET4410, and requires much more thought in usage.....Read NOT Plug-in-Play!!However, a graph of impedance vs. frequency really shows when a device doesn't behave like a simple C, or L or R and shows where it begins to misbehave!! Since you have the tools for both, you should be all setup and readyBest,

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 06, 2022, 11:31:06 pm
content: Quote from: Martin72 on August 06, 2022, 11:09:11 pmDo you have any 1000 uF electrolytics other than the Panasonic one we've been measuring so far? Do you have any other caps with capacitance slightly larger than 1000 uF, such as some 1500 uF, 1800 uF or 2200 uF?You shouldn't be getting a phase near -90 degrees at 100 kHz with a 1000 uF cap. It would be good if we could figure why you're getting this result.

author: mawyatt
author_rank: Super Contributor
timestamp: August 07, 2022, 12:29:48 am
content: Don't have anything larger than 1000uF. Here's Beryl RC016M 1000uF @ 16V and a APAQ Tech Polymer EPZ40 1000uF @ 6.3V using the technique with R = 1K shown here:https://www.eevblog.com/forum/testgear/capacitive-impedance-plots-with-sds2104x-plus-bode-function/Edit: Changed the plots to use R =100 (more test current) and moved cursor to 100KHz. I wouldn't put too much faith into these plots at higher frequencies as the kludge test setup is influencing the results.Best,

author: Martin72
author_rank: Super Contributor
timestamp: August 07, 2022, 12:30:38 am
content: Absolutely and this is why I´m doing this thing here.To find out what´s going on.The circuit design of the ET4410 is not bad, not simple(actually) and have an advantage against LCRs with chipset like DE5000, it´s "discrete"..I must have a look in my "store" if there are caps here over 1000µ, otherwise I connect several together.

author: The Electrician
author_rank: Frequent Contributor
timestamp: August 07, 2022, 12:19:18 pm
content: It would be good to have a curve of phase and capacitance vs. frequency. The ST2830 (rebadged Tonghui) has just the right intermediate frequencies--ten of them per decade. Taking measurements at all those frequencies will be somewhat tedious, but we will learn much from such curves.The old fashioned way is to plot points on a sheet of log-log paper. Nowadays you could use Excel or some other plotting program to produce the curves (logarithmic on both axes). The idea is to get curves that look like the green curves in the first image of reply #123 and the green curve of reply #126.Here is what a plot of capacitance vs. frequency for a 1000 uF cap should look like. Notice how the capacitance decreases as frequency increases until a minimum is reached. Then as the frequency continues to increase, the capacitance begins to increase as we approach the self resonance frequency. When we pass the SRF, the impedance becomes inductive rather than capacitive, and the green curve has a discontinuity and goes negative, off the bottom of the screen.

author: Martin72
author_rank: Super Contributor
timestamp: August 07, 2022, 09:03:56 pm
content: The ET4410 got a "list" function, where you can determine measure steps with different testfrequencies and let it run.Problem 1 : It got only 7 steps.Problem 2: will function fine when choosing a main parameter like Capacity, sub-parameters are some kind of buggy.But it got also scpi functionality, so you could create graphs using the interface and a suitable script/program.But with 16 testfrequencies, resolution would be poor.Therefore (not only) I´m playing hard with the thoughts to get the ET4510.It got "endless" testfrequencies between 100Hz and 100khz in 1hz steps.The rest should be the same.

author: mawyatt
author_rank: Super Contributor
timestamp: August 07, 2022, 09:12:23 pm
content: Might also check the Th2830. We got ours from Beich here. Make sure you get confirmation they will honor warranty.https://www.aliexpress.com/item/2261799944889907.html?spm=a2g0o.productlist.0.0.359533bf8sKzAb&algo_pvid=8188e631-20c5-4a39-8843-e3c406bea52f&algo_exp_id=8188e631-20c5-4a39-8843-e3c406bea52f-1&pdp_ext_f=%7B%22sku_id%22%3A%2220000000125229728%22%7D&pdp_npi=2%40dis%21USD%21850.0%21850.0%21%21%21%21%21%40210318b916599065824813386eb34a%2120000000125229728%21sea&curPageLogUid=liLHRYVUMC3eBest,

author: Martin72
author_rank: Super Contributor
timestamp: August 07, 2022, 10:16:24 pm
content: Page can not be found...

author: mawyatt
author_rank: Super Contributor
timestamp: August 07, 2022, 10:27:13 pm
content: Try this.https://www.aliexpress.com/store/1101463729?spm=a2g0o.detail.100005.2.46c23e99r0BJ8EBest,

author: Martin72
author_rank: Super Contributor
timestamp: August 07, 2022, 10:58:59 pm
content: Nope, won´t work too, if you attempt to get me directly to something.But I know what you mean, I´ll look later at Tong Hui offers.The "twinbrother" ST2830 from sourcetronic here in germany cost about 1200€ incl VAT, a little bit too much.

author: mawyatt
author_rank: Super Contributor
timestamp: August 07, 2022, 11:15:52 pm
content: Just go to AliExpress a search for TH2830, Beich should show up.Best,

author: Martin72
author_rank: Super Contributor
timestamp: August 17, 2022, 09:42:05 pm
content: Quote from: Martin72 on August 07, 2022, 12:30:38 amToo busy at work at the moment, but won´t be forgotten....Also the re-drawing of the circuit of the ET4410 is "paused" for time reasons.Both, the measure of a "big" cap and circuit drawing, will be continued in a few weeks.There is still an ambition to find out where the weakness of the ET4410 is.I got a "belly-feeling" that buying another relative cheap lcr bridge won´t get me further in this case.So the ET4510 will be my favourite if I decide to buy another one because of it´s "seamless" testfrequencies and outputvoltages.Rest of the circuit should be the same so I can continue drawing the schematic if time will allow it and as long as I got the 4410.The sourcetronic/tonghui is clearly more nicebuilding but costs more than double and as mentioned before, chances are high that they won´t get me further what accuracy in higher testfrequencies concerns.Must look if our sourcetronic still got warranty - if not, I´ll open up it´s case and take pics..

author: Martin72
author_rank: Super Contributor
timestamp: December 02, 2022, 05:51:00 pm
content: Hi,That could last a little bit longer - A hioki lcr meter claimed as defect is on it´s way to me...But it will be not forgotten, still I want to buy a ET4510, nevertheless if I could repair the hioki or not.Martin

author: gico750
author_rank: Contributor
timestamp: April 19, 2023, 02:11:36 pm
content: hello Martin, I took an ET4410, I read the whole topic and in the end I think it is a good tool lcr.If then you can make the circuit to improve let me know...thanks

author: Martin72
author_rank: Super Contributor
timestamp: June 13, 2023, 08:47:42 pm
content: Hi,Mad as I am I´ve bought a ET4410 again*, a few minutes ago - I couldn´t withstand any longer..I want to complete the schematic plus I got some ideas for a possible improvement.Should arrive in the next 3...4 weeks (china warehouse)*(sold the first for getting the hioki)

author: Martin72
author_rank: Super Contributor
timestamp: June 20, 2023, 09:41:40 pm
content: QuoteNice surprise, I´ll have it next thursday...That is pretty fast.I´m very curious about the inside, will I get again a version where all Ic´s are clear to read...

author: mawyatt
author_rank: Super Contributor
timestamp: June 21, 2023, 01:21:58 am
content: Quote from: Martin72 on June 20, 2023, 09:41:40 pmAlways wondered if some folks do this(erase IC identifications)to hide their IP, or to hide the fact they copied someone else'sEdit:addedfor clarity above.Best,

author: Martin72
author_rank: Super Contributor
timestamp: June 22, 2023, 05:26:06 pm
content: Welcome back....

author: Martin72
author_rank: Super Contributor
timestamp: June 22, 2023, 08:53:43 pm
content: QuoteYepp, again I got a version with all parts readable.But it looks different than mine before....I think, pictures from the inside and further documentations of the circuit I´ll post in the other thread - As long as it have nothing to do with the title here.

author: Andrey_Ak
author_rank: Regular Contributor
timestamp: December 20, 2023, 08:44:48 am
content: Hello. I'm sitting at work, I'm bored, I started reading this topic, I've read so far to the fourth page. I love discussions like this about capacitors and measuring their parameters.Of the devices, I have aDerEE DE-5000for a long time and this year I also bought a desktopRuoShui 4091C.When I first bought the DE-5000, I was making measurements of Soviet capacitors, and I have a lot of such capacitors, a whole collection.Here is a part of the measured capacitors:I'm thinking of continuing to measure all my capacitors, and also in comparison of these two devices and with photos of the capacitors themselves, how appropriate would it be here?

author: pope
author_rank: Frequent Contributor
timestamp: December 20, 2023, 09:34:17 am
content: Nice! Thank you!