The Great question: which ESR meter is the best for in and out of c. - Page 1
Forum section: electronics / beginners

author: RiRaRi
author_rank: Regular Contributor
timestamp: July 05, 2023, 05:46:29 pm
content: There are few good options out there for measuring ESR. I personally need it for testing caps in vintage audio gear. Which meter is the most accurate and can do in-circuit and out-circuit testing?Also, as i heard good meter has to measure at different frequencys for most accurate readings. Is LCR good investment then for this porpose?Here are few good options that i found: Peak ESR70, Blue (Bob Parker) and DER DE-5000

author: tggzzz
author_rank: Super Contributor
timestamp: July 05, 2023, 06:20:06 pm
content: Quote from: RiRaRi on July 05, 2023, 05:46:29 pmFor what purpose are you restoring the vintage audio gear? If for static display in a museum or if golden-eared audiofools are involved, then ignore the observations below. If you want to continue using the gear, then read on.I will presume that, since it is for generic audio gear, the main area in which ESR will be problematic is the power supply.Ideally you want to measure the capacitor's ESR at the frequency at which it will be used, e.g. 50/60Hz for mains rectifiers or >10kHz for SMPSs. In addition, in SMPSs a capacitor's step response may be particularly important, so that a square wave excitation may be more useful than a sine wave excitation.But, importantly, a capacitor's ESR is a poorly controlled and defined parameter. There is no single correct numeric answer to "what is a capacitor's ESR",but usually it doesn't matter. What usually matters  is that the ESR is low enough for the circuit that it doesn't cause any problems. That can usually be determined by observing the ripple voltage on the PSU.In other words, don't worry about "accuracy" (whatever that might mean). Do worry that a tester can detect whether a capacitor's ESR has grossly deteriorated. Then if in doubt, simply replace the capacitor. One exception is that some PSUs have integrated linear regulators (e.g. the 78xx and 79xx series) with tantalum capacitors on their outputs. In some cases the tant's ESR has to behighenough to ensure the regulator doesn't oscillate.

author: Vovk_Z
author_rank: Super Contributor
timestamp: July 05, 2023, 07:25:37 pm
content: RLC meters are fine for precision measurements, but they usually can't do in-circuit measurements, so they are almost unconvenient and not useful for repair or servicing old staff (as for me).I have good RLC meter (MS5308), but when I repair something I almost 100% use only in-circuit ESR/capacitance meter. It doesnt matter exact frequency if it is somewhere within 70-140 kHz.

author: bdunham7
author_rank: Super Contributor
timestamp: July 05, 2023, 08:40:17 pm
content: Quote from: RiRaRi on July 05, 2023, 05:46:29 pmI don't know whether it is a good investment for your purpose but the BK Precision 886 (discontinued) is an accurate full-featured LRC/ESR meter, uses 100/120/1000/10k/100k frequencies and most importantly for in-circuit testing, stimulus voltages of 50mV, 250mV and 1V. In-circuit testing can't always work because it depends on the circuit, but it usually does work at the low voltage settings.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: July 06, 2023, 01:34:51 am
content: The DER DE-5000 is really nice if you make the custom kelvin cables for it.Here are some reviews on it:https://www.youtube.com/@TRXLab/search?query=DER%20DE-5000

author: rhb
author_rank: Super Contributor
timestamp: July 06, 2023, 01:04:15 pm
content: I have a Peak ESR70 which is great out of circuit but useless in circuit as is the case with most of my LCR meters.The EDS-88A is the only instrument of all the LCR meters I have that will work *most* of the time. It only fails if you have caps in parallel.Reg

author: RiRaRi
author_rank: Regular Contributor
timestamp: July 07, 2023, 04:54:21 pm
content: So to sum up, maybe best ESR for servicing vintage audio can be Bob Parker design

author: EPAIII
author_rank: Super Contributor
timestamp: July 09, 2023, 02:00:57 pm
content: Vintage audio gear?Are they filter capacitors in the power supply?JUST REPLACE THEM! They are OLD and OLD electrolytics dry up. If they aren't bad now, they WILL be. Replace them and be done.Other capacitors in audio circuits?Don't trust any measurements made with them in the circuit. You MUST disconnect one of the legs if any reading is to be trusted. PERIOD. Been there too many times. This capacitor measures bad. Start removing it and check again, out of circuit and it's OK. You can't trust any in circuit checks.And 99.99% of the time that the capacitance checks OK, the capacitor is OK. Sure ESR can count. But who ever saw a ceramic or a film capacitor change it's ESR value by more than a percent or two? In over 45 years of electronic troubleshooting I only ever saw one ceramic go bad and it was shorted - DEAD SHORTED. I found that with an ANALOG multimeter. I never saw a film capacitor go bad. Never saw a silver mica go bad. So again, if it's an electrolytic, CHANGE IT. If not and the capacitance reads OK (out of circuit of course), then it is very, VERY likely 100% OK.

author: RiRaRi
author_rank: Regular Contributor
timestamp: July 10, 2023, 04:44:18 pm
content: Yes, solid state radios 70s and 80s.I am planning to replace filter capacitors in PS and also if there is another bigger one on some board.Do you think it is neccesary to replace all electrolytic caps in radios from 70s and 80s even smaller ones? or just the ones that are out of spec?

author: LinuxHata
author_rank: Frequent Contributor
timestamp: July 10, 2023, 06:57:46 pm
content: I have DER EE5000.It can't measure ESR of relatively large (above 1000uf) capacitors at high frequencies, gives error.Also, it does not remember the last setting, and ESR function is not active by default.So to measure ESR, after you power it on and connect capacitor, you have to manually press several times the mode selection button, and then several times - esr selection button.This is very silly and time consuming.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: July 10, 2023, 07:16:47 pm
content: I think the failure rate of ceramic caps is a bit underestimated by EPAIIII think I have found at least THREE (HA!) in many years of repair. Also found by multimeter.He is correct they fail in short or then if they short with a lot of power then can burn, or something else burns.Unless someone fiddles with the circuit and adds some caps or other components where they do not belong, failure of ceramics is very rare indeed. Film caps do not go bad either unless someone puts too much voltage across them. Not likely in a commercial transistor radio.Unless you are in design, I think ESR is greatly exaggerated in it's importance. We did not start to measure ESR in repair until there were inexpensive ESR meters. Repair tecks repaired lots of things without an ESR meter, and still do .Silver MICA only go bad in VERY HIgh Volt High Power RF amplifiers,in KILOVolt situations, mostly because someone put in too much power or greatly mistunes output somehow. Also in these situations everything else around the cap can burn also. This is usually a catastrophic failure of lots of components. Remember these things are made from ROCKS!!!! The leads can melt before the Mica fails.The only test I can think of in circuit for a capacitor is just a resistance check with a multimeter, If that is lower than you expect, then the thing to do is remove the cap and measure it. Or at least pull one leg off the board and then check it.Old resistors are the most likely things that go wonky over time and change value enough to affect performance.

author: RiRaRi
author_rank: Regular Contributor
timestamp: July 11, 2023, 03:21:29 pm
content: Okay. I know that other types of caps ussualy works works great on a long period of time but i want to talk about electrolytic caps. Should all electrlytic be replaced if radio/decks/other audio gear works great so it wont fail in near future (few years)?

author: TimFox
author_rank: Super Contributor
timestamp: July 11, 2023, 04:12:42 pm
content: Quote from: LinuxHata on July 10, 2023, 06:57:46 pmAt "very high frequencies" (10 kHz and 100 kHz for the DE 5000), is the total impedance of your large (1000 uF) capacitor still capacitive, or is it above self-resonance with its parasitic series inductance?At 10 kHz, the reactance of 1000 uF is 0.016\$\Omega\$ . The ESR should be less than that (if the impedance is still capacitive), which is not easily measurable.If you look at the specifications, it is only rated up to 100 uF at 10 kHz, and 10 uF at 100 kHz.Nobody measures the ESR of a 1000 uF capacitor at 100 kHz.The specifications allow 2000 uF at 100, 120, and 1000 Hz.

author: bdunham7
author_rank: Super Contributor
timestamp: July 11, 2023, 04:26:55 pm
content: Quote from: RiRaRi on July 11, 2023, 03:21:29 pmSo, to rework your question: If you take a currently working piece of audio gear, disassemble it and replace all the electrolytic capacitors and then reassemble it, is it more or less likely to fail in the next few years than if you had just left it alone?If you include the non-zero possibility that it doesn't work after you do the work, I'd say it is doubtful that you have improved your odds of having a working unit 5 years from now. YMMV, based on skill level, the actual unit in question and luck.

author: bdunham7
author_rank: Super Contributor
timestamp: July 11, 2023, 04:32:48 pm
content: Quote from: LinuxHata on July 10, 2023, 06:57:46 pmDoes the display say "PEBKAC Error" by chance?A tool with many capabilities may require more effort to understand and operate. I don't have the DE 5000, but hopefully it will allow you to measure Z,Θand D. AFAIK it doesn't have continuously selectable test frequencies, but if you make a chart of those three values using each of the available test frequencies you might better understand what is going on and why there is an error.

author: LinuxHata
author_rank: Frequent Contributor
timestamp: July 11, 2023, 07:13:43 pm
content: High frequencies in this case mean ones above 100/120hz.Even with declared capacitance and frequency ranges, it refuses to measure not only ESR, but capacitance too.For example, I connect 1500uf 10V capacitor, brand new, genuine nichicon. I connect it via the kelvin probe or contacts, whatever you call them.At 100 and 120hz, capacitance is measured and displayed, but at 1khz, it displays 0L instead of capacitance value.

author: bdunham7
author_rank: Super Contributor
timestamp: July 11, 2023, 07:36:05 pm
content: Quote from: LinuxHata on July 11, 2023, 07:13:43 pmOK, does it measure Z, Θ and D at that frequency/setting? I don't have any capacitors similar enough to yours to do any meaningful testing, but I'm assuming that the DE-5000 will display OL instead of a negative capacitance value when Θ goes positive.

author: TimFox
author_rank: Super Contributor
timestamp: July 11, 2023, 07:58:08 pm
content: Quote from: LinuxHata on July 11, 2023, 07:13:43 pmMy guess, not knowing exactly how you have wired it, is that the parasitic inductance of your 1500 uF capacitor and wiring has increased the apparent capacitance (reducing its capacitave reactance) at 1 kHz so that the reading is, in fact, over-range.When I have time, I'll check a similar capacitor on my DE5000.Please detail your statement "kelvin probe or contacts, whatever you call them" and if you did the open/short calibration at the end of those contacts before measuring your capacitor.

author: LinuxHata
author_rank: Frequent Contributor
timestamp: July 11, 2023, 08:12:33 pm
content: Yes, I have these gold plated 4 wire connectors, which plug into the slit connector in front of the instrument. I also have gold plated "jumper" which plugs into same slit for calibration purposes.The case is not with that particular capacitor, issue exists with other capacitors, roughly saying, above 1000uf.

author: TimFox
author_rank: Super Contributor
timestamp: July 11, 2023, 08:18:34 pm
content: By chance, I had a 1500 uF/10 V Panasonic radial lead capacitor.Here are my measurements, done with a TL-21 fixture from DER that I modified to use smaller alligator clips (Mueller copper).(Note that the TL-21 is "four-wire" out to the back end of each clip.)I calibrated at the alligator clips (open and short) before measurement.I measuredCS(series model) at each frequency, noting capacitance, phase angle, ESR, and Q.Contradicting my post above, the capacitance displayed at 1000 Hz decreased, rather than increased from 120 Hz.100 Hz: 1464.6 uF, -87.1 deg, 0.0\$\Omega\$, Q = 20.0120 Hz: 1449.2 uF, -86.8 deg, 0.0\$\Omega\$, Q = 18.601000 Hz: 1369 uF, -81.1 deg, 0.01\$\Omega\$, Q = 6.4210 kHz:CS"OL". ESR = 0.013\$\Omega\$.LS= 0.19 uH, -36 deg (indicating close to resonant frequency)Unfortunately, the DE5000 firmware does not displayZas an option.Personally, I wish it had R and X, or G and B as display options.I have been measuring impedance for over 40 years, first with bridges, then with bench LCR meters, and these results look normal to me.For this range of capacitance and frequency, calibration is critical and must be done as close as practicable to where the device under test is located.Specifically, if you calibrate at the front panel of the instrument, and then connect external wires (even "Kelvin connected") between the front panel and the capacitor, your results at low impedance will be wrong.100 nH of uncorrected inductance will make a big difference, even at 1000 Hz.It is quite possible that your Nichicon has a lower self-resonant frequency than my Panasonic (Matsushita) unit--it still would be well within specification.

author: bdunham7
author_rank: Super Contributor
timestamp: July 11, 2023, 08:56:14 pm
content: Quote from: TimFox on July 11, 2023, 08:18:34 pmHow does it go from capacitance to inductance without the sign of Θ changing? What sign does Θ have for regular inductors?I wonder why the left out Z, they have everything they need to display it.

author: TimFox
author_rank: Super Contributor
timestamp: July 11, 2023, 09:16:30 pm
content: My personal problems with the DE5000 are these ambiguities in measurement.I believe that what it is trying to show at 10 kHz is a very large capacitance (low reactance) that is off scale for the display.However, expressed as an inductance, that reactance is on-scale for the display.It should display the latter as a negative inductance, but it is not programmed to do so.The chipset should be easily capable of displaying Z and theta, but they didn't program that either.A quick check with a 5.6 uH RFC (mfr specfR> 83 MHz) shows a positive phase angle at 10 and 100 kHz, whereQ> 0.3.ESR = 1.09\$\Omega\$ at 100 kHz forLS= 5.590 uH, with phase angle +72.6 deg.At 100 kHz, it displaysCS= 453.1 nF with the same positive phase angle and ESR.At lower frequencies, it is essentially a 1 ohm wire-wound resistor with a small positive phase angle.In my measurements above for a nominal 1500 uF capacitor, the 10 kHz phase angle of -36 deg indicates that the frequency (10 kHz) is below the self-resonance of the capacitor, and therefore the reactance is still capacitive.Therefore, the ambiguity can be resolved by checking the phase angle, to see that it corresponds to the selected C or L mode.A bit klunky, and not mentioned at all in the manual.

author: LinuxHata
author_rank: Frequent Contributor
timestamp: July 12, 2023, 06:15:00 pm
content: Also it does not remember the setting and to measure ESR, you have to press two different buttons several times, on each power up, that's sad...

author: TimFox
author_rank: Super Contributor
timestamp: July 12, 2023, 09:22:22 pm
content: Quote from: LinuxHata on July 12, 2023, 06:15:00 pmI don't claim the DE5000 is the world's best LCR meter: that is probably from someone like Keysight or the successors to GenRad.For the money, I have found that it works well and meets specifications.I find the extra button pushing acceptable.Note that you need to be very careful about calibratinganyLCR meter when measuring roughly 1 ohm of reactance: the short-circuit calibration is especially important.I told you my exact method of calibration, and it was done after power up before measuring a 1500 uF capacitor and getting believable results.Since for that kind of action, you need to perform a new calibration anyway at power on for good accuracy, the extra button pushes are good discipline for the user.

author: bdunham7
author_rank: Super Contributor
timestamp: July 12, 2023, 09:35:01 pm
content: Quote from: LinuxHata on July 12, 2023, 06:15:00 pmQuote from: TimFox on July 12, 2023, 09:22:22 pmJust like a VNA (which it sort of is) an LCR meter that works on the principle these do needs to be calibrated right before using it and after any change in the leads or fixtures. I can't think of a single example of a good LCR meter that just fires up and does it's thing like a DMM, not even those expensive ones. My BK Precision (Motec) 886 was over $800 before they discontinued it and it requires all the care and button-pushing that the DER model does, perhaps more. It does have Z though...A plain ESR meter or a DMM-style capacitance checker works on different principles. Being more limited in function can make it simpler to implement and operate. That's not an endorsement.

author: TimFox
author_rank: Super Contributor
timestamp: July 12, 2023, 09:40:02 pm
content: VNAs work with a "reflection bridge", and require calibration to short, open, and 50 ohms with well-known standards.LCR meters do a phase-sensitive measurement of the voltage and current on and through the unknown and compute the relevant parameters from those data.They require only a short and open calibration, with no important transmission-line effects at relatively low frequencies.Especially when measuring extreme cases (high C and low C for this case), a fresh calibration is needed for both types of units.

author: LinuxHata
author_rank: Frequent Contributor
timestamp: July 13, 2023, 05:06:41 am
content: Well, I calibrated it again for sure.Zero changes.caps 1000uf and below - ok, bigger can be measured only on 100 and 120hz, above that - 0LI also had Victor 4080 LCR bridge, which has color screen and does not have that issue (but you still need to press several buttons before you reach ESR)But it started to fail, so I discarded it.

author: Shonky
author_rank: Frequent Contributor
timestamp: July 13, 2023, 06:01:39 am
content: Quote from: LinuxHata on July 13, 2023, 05:06:41 amAs per the specs. Have you looked at the manual?It will do Cs measurement up to 2000uF at 1kHz

author: TimFox
author_rank: Super Contributor
timestamp: July 13, 2023, 02:21:59 pm
content: I calibrated my unit carefully, and measure the 1500 uF capacitor according to the DE5000 specs.Note that "calibration" here really means computational compensation for the series and parallel impedance of the test fixture, and needs to be done not at the front panel but at the point where the DUT is connected.For my TL21 with small alligator clips, that means doing the "short" at the same place on the clips where the capacitor will be connected.(This type of LCR meter relies on an internal precision resistor to set the scale factors.)

author: Shonky
author_rank: Frequent Contributor
timestamp: July 13, 2023, 10:04:48 pm
content: Here's a brand new United Chemi-con EKMG250ELL222MK25S 2200uF/25V I just purchased from element 14 last week very quickly tested on my near new DE-5000 at 1kHz. i.e. it just under the 2000uF maximum range.

author: TimFox
author_rank: Super Contributor
timestamp: July 13, 2023, 10:14:11 pm
content: Looks right to me, and is consistent with my similar measurement.By democratic vote, we may conclude that LinuxHata's calibration is incorrect.

author: EPAIII
author_rank: Super Contributor
timestamp: July 14, 2023, 08:11:12 am
content: You are talking about 40 year old electrolytic capacitors! You can, of course, do as you wish, but in my experience with consumer equipment the capacitors are often sourced at the same time, from the same manufacturer and they often dry up at the same age, plus or minus a year or five. When I go to the trouble of taking an item apart and accessing the components for testing, it is not much more trouble to just replace all suspicious electrolytic capacitors. And my time is certainly worth much more than the cost of the replacement parts.That's what I do. YMMV.Quote from: RiRaRi on July 10, 2023, 04:44:18 pm