LCR tweezers 100 kHz. - Page 1
Forum section: electronics / testgear

author: iet
author_rank: Frequent Contributor
timestamp: October 11, 2024, 08:07:47 am
content: Tweezers with a measurement frequency of 100 kHz are produced. There are well-known brands that have been on the market for a long time, and there are recently appeared new models. The latest trend is to display the maximum number of parameters on the screen. There is also a tweezers with a signature analyzer function. These tweezers are distinguished by high basic accuracy, wider measurement ranges and many additional useful functions that greatly facilitate the work of those involved in electronics.Perhaps there are users of these tweezers and they could tell some interesting things based on their operating experience.https://www.lcrresearch.com/pro1plushttps://appatech.com/as/en/707https://lcr-reader.com/lcr-reader-r3.html

author: iet
author_rank: Frequent Contributor
timestamp: October 11, 2024, 10:06:08 am
content: User Manual.https://www.lcrresearch.com/_files/ugd/97c2bb_73362b7481694861a96b1bed0670c66b.pdfhttps://appatech.com/resources/APPA_707_700020056_User_manualhttps://lcr-reader.com/R3/Downloads/Documents/LCR-Reader_R3_manual.pdf

author: Feuerbard
author_rank: Contributor
timestamp: October 11, 2024, 06:50:02 pm
content: [US$79.99 20% OFF]LCR-1S Smart Tweezers LCR Tester 100kHz CNC Metal Case High Accuracy Portable 1.47" Color Display Intelligent Auto-Range Function Measurement & Analysis Instruments from Tools on banggoodhttps://ban.ggood.vip/155NTAbout $45 on taobao

author: iet
author_rank: Frequent Contributor
timestamp: October 12, 2024, 08:52:18 am
content: Specification LCR Pro1 Plus.

author: Aldo22
author_rank: Super Contributor
timestamp: October 12, 2024, 10:08:34 am
content: The specifications look very good, but the price is quite high for this type of device.https://www.batronix.com/shop/lcr-meter/LCR-Research-Pro1-Plus.html

author: iet
author_rank: Frequent Contributor
timestamp: October 12, 2024, 05:32:53 pm
content: The price is set by the manufacturer, based on the specification and functions of the device.Most of the price is probably related to the frequency of 100 kHz or not?

author: Aldo22
author_rank: Super Contributor
timestamp: October 12, 2024, 06:01:58 pm
content: Quote from: iet on October 12, 2024, 05:32:53 pmAs I said, the specs sound good, but would I want to buy it for that price?You can buy aUNI-T UT622Eplus a Zoyi MD-1 (for quick and dirty) and still pay 100 euros less.But maybe it's worth it? I haven't compared all the specs.

author: Sensorcat
author_rank: Regular Contributor
timestamp: October 12, 2024, 09:21:46 pm
content: I have the LCR Pro1 Plus. Since I need it for work, I had a priority on performance and quality, not price.Advantages:very good built qualitybright displaywell-thought user interfacevery competent reply to email with highly specialized questionsThe email contact was three or four times and customer support of Keysight, Tektronix, LeCroy, or R&S could learn a lot from LCR Resaerch...There is much cheaper competition, but I would recommend it if the price is not a problem.

author: iet
author_rank: Frequent Contributor
timestamp: October 12, 2024, 09:53:41 pm
content: Quote from: Aldo22 on October 12, 2024, 06:01:58 pmLCR Pro1 and LCR Reader MPA are very close in price and occupy the segment of the most expensive smart tweezers. There is very little information on their real practical application, so everyone decides for themselves whether to buy expensive tweezers.

author: iet
author_rank: Frequent Contributor
timestamp: October 12, 2024, 10:09:54 pm
content: Quote from: Aldo22 on October 12, 2024, 06:01:58 pmYou will also have to buy tweezers of this model for it.https://www.ebay.com/p/1337077889?iid=186269591071

author: iet
author_rank: Frequent Contributor
timestamp: October 12, 2024, 11:10:38 pm
content: Quote from: Sensorcat on October 12, 2024, 09:21:46 pmI would like to see these devices in real work. In the pictures everything is very beautiful.

author: Aldo22
author_rank: Super Contributor
timestamp: October 13, 2024, 09:08:02 am
content: Quote from: iet on October 12, 2024, 10:09:54 pmYes, that is correct. UT622E comes with “Four-terminal Kelvin test leads”.There are also Uni-T branded tweezers, but they are probably the same product as the one you showed.https://youtu.be/SZRRKZ4T6oAStill cheaper.You might ask Sensorcat if he would have bought the LCR Pro1 Plus if he had to pay for it with his own money.I mean, a Siglent SDS804X HD costs about the same (just for comparison).But I'm sure it's great if you don't care about the price.

author: iet
author_rank: Frequent Contributor
timestamp: October 13, 2024, 08:47:27 pm
content: Quote from: Aldo22 on October 13, 2024, 09:08:02 amDepending on the type of work, we choose either a good oscilloscope or tweezers. And it is better to have both. As for the comparison of tweezers, it is better to compare them in real measurements and over the entire range.

author: iet
author_rank: Frequent Contributor
timestamp: October 14, 2024, 01:54:42 pm
content: Drift in the open state in the third decimal place.I have already taken measurements in another topic, in the picofarad range. I got a few more 1 pF capacitors. And here is the total capacity of 8 capacitors connected in series.

author: Aldo22
author_rank: Super Contributor
timestamp: October 14, 2024, 02:21:30 pm
content: Quote from: iet on October 12, 2024, 11:10:38 pmWhat is actually your point?Apparently you own these tweezers, so what's your question?Is this just about advertising?

author: iet
author_rank: Frequent Contributor
timestamp: October 14, 2024, 02:33:25 pm
content: Quote from: Aldo22 on October 14, 2024, 02:21:30 pmThe point is that I showed how the tweezers work in the picofarad range, that is, their capabilities and compliance with the specification.My topic does not have advertising videos and pictures, like others.

author: iet
author_rank: Frequent Contributor
timestamp: October 15, 2024, 09:26:48 am
content: My topic is about tweezers with a maximum measurement frequency of 100 kHz. This is the main difference from other tweezers with a maximum measurement frequency of 10 kHz.Why do you need a frequency of 100 kHz? Let's look at the specification. 100 kHz is used in the nH and pF range. In addition, this frequency is used to measure the ESR specified in the documentation for different types of capacitors.I have already checked the picofarad range, now the nH range.I solved the problem this way. I bought smd resistors with the designation 0. The inductance of such a resistor is 5 nH. I connected 6 resistors in parallel.

author: Kean
author_rank: Unknown
timestamp: October 15, 2024, 10:27:46 am
content: Quote from: iet on October 15, 2024, 09:26:48 amI've noticed in your various topics on LCR tweezers that you post many photos of measurements, but you rarely make any observations of the result.Like Aldo22, I am not sure the point you are trying to make.It is not obvious if you have made any efforts to "fudge" the numbers.You don't explain if you had to do any special short/open calibration to get these readings.You don't compare the measurements to bare side-by-side pads/traces on a PCB - e.g. in your earlier sub pF measurementYou don't compare the results against the device specification.For example, in this reading with 6 parallel "5 nH" 0R resistors...How does that result meet your expectation considering the tool has an accuracy spec of "2.5% + 5nH" in the 1000nH 100kHz inductor range?

author: mawyatt
author_rank: Super Contributor
timestamp: October 15, 2024, 04:21:20 pm
content: Quote from: iet on October 15, 2024, 09:26:48 amPlease note that placing 6 SMD Inductors in parallel like shown does not create an overall inductance that is 1/6 the single value inductance. The individual H Fields couple and the overall inductance is influenced by such and doesn't follow the lumped element 1/n parallel rule.If you think of a wire inductance, the inductance is not inversely proportional to the wire diameter but more complex as Grover's Equation predicts. The change in inductance wrt the wire diameter (dL/dD) is much slower than expected by simple paralleling as 1/D would expect.https://www.allaboutcircuits.com/tools/wire-self-inductance-calculator/The same goes for a Flat wire, the overall inductance is not inversely proportional to the flat wire thickness as shown here:http://www.finetune.co.jp/~lyuka/technote/inductor/inductor-straight-flat.htmlFor example, a 2512 Zero Ω Resistor should have 2.2~2.5nH self inductance, and a 1206 1.5~1.8nH based upon the above. Note these are highly dependent on many variables, some not accounted for in the listings but should give a rough estimate of the expected self inductance.So from your example we don't think the individual self inductance of the SMD resistor shown is ~5nH, likely much less, and the parallel result is also in question.BTW look at the impedance of the DUT at the expected frequency, for example 1nH is just ~0.63mΩ @ 100KHz, that's going to be very difficult to resolve considering the limited test current available from the tweezers. This is where a quality Bench Lab Grade LCR meter earns it's keepBest

author: Sensorcat
author_rank: Regular Contributor
timestamp: October 15, 2024, 10:51:06 pm
content: In addition to the explanations of mawyatt in reply #18, it is important how the 6 resistors are geometrically arranged, as the inductance of the wiring contributes significantly to the overall inductance at these small values. Unfortunately, the image in reply #16 does not show this. We see only one element and have to guess where the other 5 are. With a few mm of wiring (or not) from element to element and instrument, everything is possible from less than the expected value of the lumped element model parallel connection, to much more. So we cannot draw any conclusion from what is shown there.While I'm at writing: Aldo22, since it is my business, I did spend my money on the LCR Pro1 Plus. What changes if you buy for your business is the value of time. In business, 'time is money'. In hobby work, there is no monetary value in time. So business owners tend to invest more in tools, if they expect to save time in any way. This is a trivial, please don't think I want to lecture you, but there is something that I discovered only when I began to be in the situation of the business owner: The issue of time is already at work in procurement. That means, if buying the more expensive instrument is expected to save time by 'being done with buying' for a class of instrument and a couple of years, the business owner is often inclined to invest more, to get the job of buying finished. In that sense, I do not regret the decision for the LCR Pro1 Plus.

author: mawyatt
author_rank: Super Contributor
timestamp: October 15, 2024, 11:15:27 pm
content: Quote from: Sensorcat on October 15, 2024, 10:51:06 pmWe had "assumed" the SMD resistors were stacked one on top another per the image, and thus using the {wire cross-section} equivalent to show the relationship on inductance with paralleled devices or conductor "thickness". Of course this "assumption" could be totally wrong!!Best

author: iet
author_rank: Frequent Contributor
timestamp: October 16, 2024, 11:22:23 am
content: Thanks to everyone for the comments.I didn't even think that measuring the inductance of 6 resistors connected in parallel would cause such a violent reaction. Naturally, there is nothing extra there. The resistors are simply soldered together. I wanted to check the ability of the tweezers to measure inductance less than 1 nH, and not get an accurate result. If I had inductances of 0.1 nH, then we could talk about accuracy.Therefore, I would like to ask the developers of LCR Pro1 and LCR Reader MPA how they check their parameters from the specification.

author: iet
author_rank: Frequent Contributor
timestamp: October 16, 2024, 12:35:28 pm
content: Quote from: mawyatt on October 15, 2024, 04:21:20 pmAxial inductors 1 uH - 10 pcs.Average value - 880 nH. Connected 5 pcs. in parallel. Inductance 170 nH.It seems to work in some ratio.I removed 4 SMD inductors with an inductance of 300 nH from the board and soldered them in parallel. The situation is similar to the previous one.

author: mawyatt
author_rank: Super Contributor
timestamp: October 16, 2024, 04:33:50 pm
content: Quote from: iet on October 16, 2024, 12:35:28 pmYes but not the 1/n as implied, probably more like 1/(n^x + k*n + b) or 1/(n^x) + k*n + b, where n is the number of paralleled inductors, x, k and b are constants/variables that depend on DUT Inductor test frequency, type, size, orientation, connection method, and proximity effects.Point is it's not a simple 1/n as implied by paralleling equal valved resistorsBest

author: iet
author_rank: Frequent Contributor
timestamp: October 16, 2024, 04:47:31 pm
content: Quote from: Kean on October 15, 2024, 10:27:46 amI already wrote about this in another thread.For correct measurement in the picofarad range, two things must be done.Calibration with closed and open probes.The distance between the capacitor leads must match the distance between the tweezers tips. If the distance does not match, the error will increase.All this is well analyzed and entered into the table in the information from LCR Reader.https://www.wnie.online/wp-content/uploads/2021/02/Siborg-Systems_Accurate-Measurements-of-Extremely-Small-Capacitance-Values-2.pdf

author: iet
author_rank: Frequent Contributor
timestamp: October 16, 2024, 05:27:54 pm
content: I will give another example. Ceramic capacitor 0.47 pF. The distance between the capacitor terminals exactly matches the distance between the tweezers tips.

author: mawyatt
author_rank: Super Contributor
timestamp: October 16, 2024, 06:00:00 pm
content: Quote from: iet on October 16, 2024, 05:27:54 pmAt ~ 0.48pF @ 10KHz the DUT impedance is ~33MΩ and test current is only ~30nAAt this high Z level we would put more faith in a mechanically & electrically stableSDMSMD Test Fixture with an LCR Meter than tweezers where hand placement, tweezer orientation, DUT orientation & mounting all can have significant measurement influences.Best,

author: iet
author_rank: Frequent Contributor
timestamp: October 17, 2024, 07:01:59 pm
content: LCR Reader offers its own method for measuring extremely small inductance values.https://www.lcr-reader.com/documents/AutoTestCon_2022.pdf

author: mawyatt
author_rank: Super Contributor
timestamp: October 17, 2024, 08:10:32 pm
content: Quote from: iet on October 17, 2024, 07:01:59 pmWell that's an interesting paper, as it seems they don't even know how to properly calculate the impedance of an inductance, which leaves everything else in questionThat alone kept us from reading any further than the introduction, as obviously this paper hasn't had any peer review!!Thanks for the link, this is a good example of why folks shouldn't believe and value everything they get on the internet. Even papers that seem to "Look Official", and emphasizes that one shouldknow basic electrical & measurement fundamentals and limitations of suchbefore believing everything they read.As we said many times KTI (Know Thy Instrument), especially true for extreme measurementsBest

author: shabaz
author_rank: Frequent Contributor
timestamp: October 17, 2024, 10:58:05 pm
content: To be fair, even seminal papers have had errors occasionally (some of which are not detected for decades). I noticed the error in the abstract, a decimal place slip-up, granted it shouldn't be there if it was checked. But it would be good to know if there's any deeper mistake in the paper or not (especially if maybe if the authors could see this and explained themselves why they are confident in what they wrote, and accepted the mistake).

author: Sensorcat
author_rank: Regular Contributor
timestamp: October 18, 2024, 12:55:38 am
content: Quote from: shabaz on October 17, 2024, 10:58:05 pmAn error is OK, but simply everything is defective in this paper, such that actually no method is disclosed. The author does not describe his measurement setup, instrument settings, part numbers of specimen used, calculations performed. The results shown in the plots just spring into existence. And then this fuzzy language, that does not explain, does not provide a design or research goal, draws no conclusion. Formal errors on top: ridiculous references, two sections with the same title. A joke camouflaged as a scientific paper. Pauli would probably say: "It is not even wrong!"

author: shabaz
author_rank: Frequent Contributor
timestamp: October 18, 2024, 01:59:22 am
content: There are many papers where numbers are summarized, with the raw data not there. Anyway, that's a different thing to what I mentioned. I don't know if the paper has other mistakes or not, and it may well be the quality is lacking in other ways.However, even for a novice, it seems to indicate quite clearly what (at least part of) the secret sauce is that may (or may not, I know nothing of their product) provide better results at small inductances for their LCR tweezers. I don't know what the specification is for that product (I'm not in the market for spending that much on LCR tweezers), but it certainly makes clear that the specification relies on some assumptions about the geometry of the inductor for low inductances. For that at least, the paper was interesting. By the way, please note I'm not being argumentative nor even playing devil's advocate here. I'm not interested in that. I just happened to look at that paper out of interest and noticed that error. I'm not in the market for these LCR tweezers, nor do I own any. I do use other tools to measure inductances occasionally.

author: Kean
author_rank: Unknown
timestamp: October 18, 2024, 03:28:11 am
content: I only skimmed the "paper", but it seemed to basically offer a rule of thumb (fudge factor) for getting "more accurate" measurements... for when you are using the wrong tool for the job.I didn't spot the calculation error someone mentioned, but the graphs all using different color keys was very poor form.I haven't gone searching the LCR Reader/Siborg website to see if they offer more detail on accuracy specs. Other manufacturers have those handy charts that show how measurement accuracy is affected by multiple variables - most notably the combination of value vs test frequency.

author: egonotto
author_rank: Super Contributor
timestamp: October 18, 2024, 03:34:00 am
content: Quote from: mawyatt on October 17, 2024, 08:10:32 pmHello,I can only see one formula in the rather confusing paper. And this seems to want to correct a measured value by an offset and a factor.Could you please tell me where an impedance of an inductance is calculated incorrectly.Best regardsegonotto

author: shabaz
author_rank: Frequent Contributor
timestamp: October 18, 2024, 04:27:43 am
content: Hi,It's in the abstract (they mention 6 milli-ohm and 60 milli-ohm, but their decimal point is wrong by one place.As you say, they are simply correcting by an offset+factor, based on the measured value. It doesn't seem novel, just seems to be some form of small justification of why they do it. Relies on the fact that they are hoping that a small inductance is likely to be in a small (0603 or smaller) package.

author: mawyatt
author_rank: Super Contributor
timestamp: October 18, 2024, 12:59:50 pm
content: Quote from: Kean on October 18, 2024, 03:28:11 amIn the Introduction, a 1nHImpedanceat 100KHz is ~0.6 milli Ω, not 6 milli Ω, and at 1MHz ~6 milli Ω, not 60 milli Ω as stated.One could "forgive" this as a decimal slip (twice) except it's right up front in the Introduction and thewhole subject is about measuring low Z inductance where this is the Parameter of Discussion!!Obviously no peer review and note how the paper is configured as an IEEE type paper, kind of implying it's an IEEE paper which it's not!!Anyway, agree this seems more about using the wrong tool for the job, a little advertising for the their LCR tweezers, and using "fudge factors" without any details of how these were derived. Very little valuable technical content IMO.Best

author: egonotto
author_rank: Super Contributor
timestamp: October 18, 2024, 04:34:59 pm
content: Hello,But there is one good point in the paper, namely:" Chapter: Inductance Measurement, by Michal Szyper, Measurement, Instrumentation, and Sensors Handbook, Edited By John G. Webster, Halit Eren, eBook Published January 31, 2017, CRC Press"Best regardsegonotto

author: shabaz
author_rank: Frequent Contributor
timestamp: October 18, 2024, 06:56:34 pm
content: Quote from: mawyatt on October 18, 2024, 12:59:50 pm"the wrong tool for the job"That's a good point, but it raises the question, what is the job? It depends. Taking me as an example: If I'm making the effort to measure an inductor precisely, then I'll measure it ideally at the frequency of operation, and sometimes within a larger network, and I'm prepared to spend the time setting it up, there will be a time investment of say 10 minutes or more, depending on what tools I'm using and if I decide to plot the results or not. It's rare I would want precision, because many circuits can be trimmed in one way or another to reach precision without requiring the inductance to be initially precise. Besides, there may be plenty of temperature dependence, or component tolerance, so one might not fully rely on the inductance precision anyway.However, if I ever had a need to do a spot-check to confirm the ready-made tiny SMD inductor I've picked up is 10nH or 22nH nominal, then I believe users like me would not need to care if the measurement error is in tens of percent. For that reason, from my perspective I could only get interested in a pair of LCR tweezers if:(1) they supported measurement with a granularity of at least 10 nH for the low inductances, and(2) if they were cheap(er), because I would not be using them for precision measurementsMaybe (1) can only be achieved well in a small form-factor if there's really a 4-wire measurement going on fairly close to the probe tips (if it cannot be possible right at the probe tips) - I don't know if any LCR tweezer manufacturer is doing that or not.From the few photographs in this thread, it does seem to appear that nH and tens of nH can be measured in a tweezer form-factor to at least some degree of success. There's still not a lot to go on, but it looks plausible from the photos. But I'd like to see more evidence, and a lower cost. Until then, personally I'm only interested in handheld or desktop instruments; if I'm spending several hundred $ then I don't see the benefit of tweezers when for a similar cost, I can get a handheld instrument that will work down to nH.Of course, just because LCR tweezers do not meet my needs, doesn't apply to others, they will have a different job to apply it to.For instance, if I was doing production work, then that's a different kettle of fish. Maybe the product being produced uses no inductances that low. In that case, I could find the tweezers very useful perhaps. And I'd be prepared to spend a decent amount on the tweezers more for the reliability rather than precision.I don't know, because I don't do production work.

author: Kean
author_rank: Unknown
timestamp: October 19, 2024, 05:12:33 am
content: Quote from: shabaz on October 18, 2024, 06:56:34 pmWhen I used that phrase earlier, I was referring to what iet was trying to show. And to a lesser extent, what that paper was promoting (i.e. use of their products beyond specification)I don't know iet's use case or intentions, but it seemed to be showing off or shilling products. Maybe just fanboy-ism.In general I do use SMD tweezers regularly (not quite daily), but only for a quick component value check.e.g I have small container of passives that have come off my PnP machines that I keep handy for prototype or rework. I know it is full of my most common values, so saves me having to pull out a bag from stock.I wanted some SMD tweezers for so long, but the price was too high for my usage. I now mostly use the Shannon tweezers, and I'm very happy with them.I also have some cheap ones which are rubbish. I don't recall the brand/model but they are bright yellow and quite bulky, but handy to keep at my other workbenches.If I want to do any kind of precision measurement, I will use my bench LCR (a CKT5000) with an appropriate fixture. I often use it to graph frequency sweeps, which just isn't practical with tweezers.Sometimes I will need to go beyond 5MHz and will use my tinyVNA or LiteVNA64, but then the setup/fixturing is even more important.

author: shabaz
author_rank: Frequent Contributor
timestamp: October 19, 2024, 06:00:53 am
content: I couldn't tell if it was astroturfing either, which is annoying if it is : (What you mention about a quick component check is pretty much all I would want too, with that caveat of needing checks below 100 nH. So for the same reason, I find these tweezers too high priced for my usage too.It would be nice if a manufacturer addressed the market for those who do not actually need much accuracy from a tweezer device, but do want the granularity down to nH or tens of nH. Maybe that market just isn't all that large : ($395 (which is just one midrange price for the LCR-Reader, there are even higher!) is crazy.. it puts it squarely outside of what I would value such a product (because I would not want to pay for accuracy I did not need for quick spot checks). Personally, even $200 is too high for the very basic use I would put it to, so unless it comes down in price a _lot_, it's an uninteresting product for me.Totally agree with the setup time with the VNA, which is massive compared to LCR tweezers. I don't mind that, since if I'm using the VNA then I do want the deeper insight, and that's time well spent usually. I always end up learning something each time!

author: Sensorcat
author_rank: Regular Contributor
timestamp: October 20, 2024, 01:35:54 am
content: Quote from: shabaz on October 19, 2024, 06:00:53 amYes, I guess this specific market must be small, because people who need to measure inductors less than 100nH will usually have other ways to do that, most probably also at higher frequencies. But I also think that no one wants to offer that in the lower price range because small inductance ranges are difficult to implement with the tweezer form factor:Higher test frequencies are necessary, but that will drive the bill of materials up.Higher test currents will help, but that will deplete the small battery fast.4-wire connection will improve accuracy and stability, but is tricky with tweezers (who wants to have an instrument that always complains that the connection to the DUT is incomplete?). I'm not aware of any offer, either tweezer instrument or tweezer test fixture, that brings 4-wire connection to the DUT, such that contact resistance is eliminated, too. And exactly that would deliver RF properties of the device, both real and imaginary part.So it's 'wrong tool for the job' for small inductors by design principle, I would say. For anybody who does not need that and is price sensitive, this could be an option:https://www.mastech-group.com/global/en/ms8911.htmlThat is not a recommendation, I never had one and do not know how well it performs. But it looks quite attractive on paper.

author: shabaz
author_rank: Frequent Contributor
timestamp: October 20, 2024, 02:12:58 am
content: That looks quite good for users who need a quick check and (like me) don't care about high accuracy in this form-factor.I guess if there was some matrix of these parameters like price, granularity for low-value components, and size, and speed-of-use, in the absence of LCR tweezers with that sensible price and granularity at the low end, then I'd probably gravitate toward something like Extech LCR200 attached to 2-wire tweezers for the times I didn't want any accuracy, and wired to a DIY 4-wire measurement setup for the times I did. It's cheaper than the LCR Reader product, and more expensive than the Mastech, and not as speedy as picking up LCR tweezers, but probably would suit me more.I've had my eye on that Extech for quite a while (and might bite sooner if I come across a bit of a discount, even though the price seems very fair, I can't complain), but have just resorted to other tools for the time being.

author: mawyatt
author_rank: Super Contributor
timestamp: October 20, 2024, 02:39:32 am
content: Another issue with tweezers, either the fully complete types or the types for use with a bench LCR meter is the effects of the users hands on the measurements. If the tweezer handles host unshielded wires to the blade tips, the users hands can have an influence on the results, this is more pronounced with higher Z measurements such as small capacitors.Some quality tweezers for use with bench LCR meters like the Tonghui TH26009B and various clones, have shielded cables up to the tweezer blade tips for all 4 wires in a Kelvin arrangement. This works well shielding the users hand effects and also extends the tweezer frequency range to 15MHz for the TH26009B.Best

author: iet
author_rank: Frequent Contributor
timestamp: October 20, 2024, 02:55:31 pm
content: Quote from: shabaz on October 19, 2024, 06:00:53 amThis LCR tweezers may match your request.TH2822M-230$.https://www.ebay.com/itm/225599830680

author: shabaz
author_rank: Frequent Contributor
timestamp: October 20, 2024, 03:53:28 pm
content: Thanks for the link, I'll check it out soon.I have a Tonghui bench LCR meter, I like it.

author: mawyatt
author_rank: Super Contributor
timestamp: October 20, 2024, 05:07:31 pm
content: Quote from: shabaz on October 20, 2024, 03:53:28 pmCaution, Tonghui is very strict about dealing with products from unauthorized dealers/resellers, could end up with no warranty and have to deal with warranty claims from the reseller.Also, check the ebay resellers rating and reviews, very questionable source IMO.Best

author: iet
author_rank: Frequent Contributor
timestamp: October 22, 2024, 06:47:39 pm
content: Quote from: Sensorcat on October 20, 2024, 01:35:54 amThose tweezers that have appeared recently can also measure inductance up to 100 nH, based on the technical characteristics. I can definitely say about Fnirsi ST1.If we consider only inductance measurement, then it is cheaper than MS8911.And its measurement speed is higher.Measuring smaller inductance values ​​is a slightly different circuit, components, implementation and price. Everything has its own cost.

author: iet
author_rank: Frequent Contributor
timestamp: October 23, 2024, 02:23:02 pm
content: Information from the LCR Pro1 on accurately measuring small inductance.https://www.lcrresearch.com/post/use-lcr-pro1-smart-tweezers-style-lcr-meter-to-measure-small-inductors-accuratelyNow I'll tell you where the LCR Pro1 tweezers can help in real practical work.When I made the tweezers, the 100 kHz ESR meter, I had to measure the inductance of the primary and secondary windings of the transformer very accurately. Here, nanohenries are not so much needed as high resolution. There must be a strictly multiple ratio of inductances. Like 550 nH and 550 uH. Then we can easily get the rest of the parameters.This also applies to checking the inductance of the windings of factory transformers.The second use of the tweezers is measuring the inductance of SMD calibration resistors. Because the smaller the inductance of the resistor, the smaller the error in calibrating the scale.

author: mawyatt
author_rank: Super Contributor
timestamp: October 23, 2024, 06:41:21 pm
content: Quote from: iet on October 23, 2024, 02:23:02 pmThat link is interesting, we like the resolution of the Pro1 Tweezers down to pH, 10X better than the lab Tonghui LCR Meter with TH26009B Tweezers, we must remember that a pH @ 100KHz is just 628 nΩ (yes nano ohms)The TH26009B Tweezers for LCR Meters are some of the better tweezers available IMO, and the cost reflect this. They have shielded wiring thru the handles up to the blade tips and do a good job with various size SMD components.We have both the Tonghui TH2830 LCR Meter and the TH26009B Tweezers and decided to run a quick test of SMD inductors @ 100KHz like the article. We did the Open Short Cal with the Tweezers a few times, even cleaned the blades with IPA, but can't get a repeatable Short reading within at least +-0.5nH as often as we tried. This uncertainty also reflected sometimes even higher in various SMD Inductor measurements in the 10nH to 500nH range shown with various SMD sizes starting at 0201 like shown below. If we change the our hand pressure, move hands around, or change tweezer orientation we can get readings of just about anything we want around the inductor valueThis type behavior is exactly why we invested in various SMD Fixtures for SMD devices, some OEM, some modified and some custom, where we needed accurate and repeatable resultsBest

author: iet
author_rank: Frequent Contributor
timestamp: October 23, 2024, 07:55:35 pm
content: It would not be entirely correct if I comment on the capabilities of these tweezers for the developers.I can only answer for myself. I never post things on the forum that have not been tested in practice. Any low values ​​of the measured quantity must have a certain stability of repetitions. For me, this is the criterion of truth. If there is no stability, then it is necessary to analyze the entire measurement chain.I appreciate your efforts in implementing different devices for different types of measurements. In general, I like people who do something and not just write long texts with deep thoughts on the topic of measurements. And it is even worse if they come up with different fantasies, attributing them to the topic starter.In such an unstable range, it is difficult to make comparative measurements, being in different conditions.I do not have a cool desktop device to check the result. I will now make a short comment and show the measurement results. If you can repeat the same on your cool device, I will be very grateful to you.A good tweezers in the nanohenry range should react to a piece of copper wire. Such measurements were made with a piece of copper wire 0.65 mm, information is in the article from LCR Reader. I also made such measurements with a piece of copper wire 0.65 mm: 5 mm, 2.5 mm, 1.25 mm.

author: mawyatt
author_rank: Super Contributor
timestamp: October 24, 2024, 01:01:46 am
content: Quote from: iet on October 23, 2024, 07:55:35 pmThose values don't agree with what is predicted by Grover's formula.https://www.allaboutcircuits.com/tools/wire-self-inductance-calculator/Even the wire resistance doesn't agree.https://www.omnicalculator.com/physics/wire-resistanceBest,

author: indman
author_rank: Super Contributor
timestamp: October 24, 2024, 05:42:33 am
content: Quote from: iet on October 23, 2024, 07:55:35 pmIt is the creation of fantasies, unsupported by serious evidence, that you are engaged in your topics on the forum

author: indman
author_rank: Super Contributor
timestamp: October 24, 2024, 05:48:15 am
content: Quote from: mawyatt on October 23, 2024, 06:41:21 pmThank you for the test, this once again proves that measuring such small quantities with tweezers is difficult and it is very difficult to get stable results, even with such high-quality instruments and devices as yours.

author: mawyatt
author_rank: Super Contributor
timestamp: October 24, 2024, 03:28:56 pm
content: Just for fun we took a 2mm dia 5mm long Copper wire for measurement. This calculates as 1.74nH (Grover) and 0.0267 milli-Ω.First was using the TH2830 LCR Meter and TH26009B Tweezers @ 100KHz, we couldn't get any type of stable readings and the results wandered from 10~13nH and 0.05~0.5Ω based upon hand pressure, orientation, and repeated DUT engagements.Then we used the SMD Fixture as shown with the TH2830 LCR Meter, here the results were much more stable and much closer to the computed values but still some slight uncertainty. Note the test current and DUT voltage.If the DUT were flat we could use our custom Split-Kelvin Fixture for even better results, which was specifically developed for these low Z measurements.We just can't see how any type of tweezers, even dedicated LCR Meter quality types like the TH26009B can achieve accurate repeatable results at impedance extremes. We've tried over the years to achieve this without success and why we developed the custom LCR Meter Fixtures and modified SMD Fixtures to improve measurement results.Anyway, guess our skills, techniques and equipment aren't up to par with those articles and those folks here, that can achieve these remarkable results with Tweezers at impedance extremesBest

author: indman
author_rank: Super Contributor
timestamp: October 24, 2024, 03:38:30 pm
content: Quote from: mawyatt on October 24, 2024, 03:28:56 pmAll correct and your results match my experience with such measurements.Like the author of this topic, I can take 100 photos showing the result of 1 randomly matched measurement. But this does not mean that such measurements with tweezers will be correct and reliable. You just have to realize this and keep it in mind in your work.

author: mawyatt
author_rank: Super Contributor
timestamp: October 24, 2024, 04:16:46 pm
content: BTW one can do a "sanity check" without any reference standards or such. Simply do a Zero Ohm Short Calibration (Tweezer Blades together), then measure the inductance of the Short with repeated engaging and disengaging (opening and closing) the Tweezers. That reveals the uncertainty in a Short, and likely anything else you measure will have more uncertainty.Best

author: mawyatt
author_rank: Super Contributor
timestamp: October 25, 2024, 03:37:02 pm
content: There was discussion about measurement ranges over here:https://www.eevblog.com/forum/testgear/upgrade-from-a-der-de-5000-lcr-meter/These are graphs that show the range limits of measurement with the Tonghui TH2830 and Hioki IM3536 Lab Grade Bench LCR Meters. Note the limits on Impedance, Inductance and Capacitance measurements. The IM3536 achieves lower Inductance limits by means of a larger available DUT test current (and higher frequency range) of 100mA RMS vs the TH2830 33mA RMS. Please note these graphs assume a proper Calibration, Measurement Technique and Fixture for a given DUT.Hopefully this will illustrate the realistic limitations of DUT measurements for various types of LCR instruments, with ranges over 10 decades for the TH2830 and 15 decades for the IM3536Please note the error in the TH2830 Graph, the upper right corner should be 10fF not 10pF as shown, we illustrated this in RED as a note.Best

author: indman
author_rank: Super Contributor
timestamp: October 25, 2024, 05:22:46 pm
content: Quote from: mawyatt on October 25, 2024, 03:37:02 pmYour expensive meters are inferior in measurement limit to this simple and cheap L meter for $2-3The photo and design are not mine, just look at the small inductances it measures!?

author: iet
author_rank: Frequent Contributor
timestamp: October 28, 2024, 03:21:16 pm
content: Tweezers 100 kHz QPLink LCR 1S, reply 2.The main features are similar to LCR ST1. There are some differences.Frequency 100 kHz.Measurement voltage: 0.1 VVoltage Range: ±0.1 V to ±16 VBattery Capacity: 500 mAhIntelligent Auto-Range FunctionWatched the video. I liked the good stability of the numbers, the speed of measurements.It is difficult to assess the quality of the tips of these tweezers yet.Instead of the value of 0.6 V of the measurement voltage, it is better to make 1 V.In the range of resistance measurements, do I need to correct 1 Ohm?https://www.bilibili.com/video/BV14usaeWE1g/?spm_id_from=333.337.search-card.all.click

author: mawyatt
author_rank: Super Contributor
timestamp: October 28, 2024, 04:39:58 pm
content: Quote from: indman on October 25, 2024, 05:22:46 pmYes, those are far superior instruments and measurementsBest

author: iet
author_rank: Frequent Contributor
timestamp: November 14, 2024, 08:05:26 pm
content: Measuring the ESR of capacitors.I will make measurements at a frequency of 100 kHz with different tweezers. My attention will be focused on capacitors with low ESR. These are solid polymer capacitors, polymer SP Cap, tantalum and electrolytic low ESR.For this purpose, a new tweezers measuring at a frequency of 100 kHz was designed. Basic information is here.https://www.eevblog.com/forum/projects/esr-meter-with-extended-scale/The tweezers are completely autonomous and allow you to install a 50 uA microammeter on it. A powerful 1900 mA battery and a charger are installed. The tips are made of polished brass. The tweezers have a universal power supply: from a battery and an external power supply and are switched on by a microswitch.The scale is 0-100 mOhms.The scale was calibrated with SMD resistors.I made a test board.Measuring SMD resistors.

author: iet
author_rank: Frequent Contributor
timestamp: November 14, 2024, 10:48:06 pm
content: Measuring SMD resistors.

author: iet
author_rank: Frequent Contributor
timestamp: November 20, 2024, 01:42:34 pm
content: Measuring the ESR of capacitors.I made a test board.Solid polymer capacitors.

author: tautech
author_rank: Super Contributor
timestamp: November 20, 2024, 07:31:00 pm
content: Quote from: iet on November 20, 2024, 01:42:34 pmhttps://www.eevblog.com/forum/testgear/lcr-cal-test-pcb/

author: indman
author_rank: Super Contributor
timestamp: November 21, 2024, 07:18:28 am
content: Quote from: iet on November 14, 2024, 08:05:26 pmYou have already been repeatedly hinted in other topics - this circuit does not measure ESR, it measures the total resistance (impedance) - Z!!!

author: iet
author_rank: Frequent Contributor
timestamp: November 21, 2024, 09:39:17 pm
content: tautechNice pcb.Solid polymer capacitors.

author: tautech
author_rank: Super Contributor
timestamp: November 21, 2024, 10:13:29 pm
content: Quote from: iet on November 21, 2024, 09:39:17 pmJosh has some for sale:https://www.eevblog.com/forum/buysellwanted/fs-lcr-cal-test-pcb-v5-(bare-pcbs-only)/

author: iet
author_rank: Frequent Contributor
timestamp: November 22, 2024, 10:04:33 pm
content: tautechThanks for the link.SP-Cap polymer capacitors.

author: iet
author_rank: Frequent Contributor
timestamp: November 26, 2024, 05:23:30 pm
content: I would like to dwell in more detail on the ESR measurement of the SP-Cap polymer capacitor of the GY Super low ESR 820 uF-2 V series.According to the datasheet, the max. ESR is 3 mOhms. If you look at the ESR/Impedance dependence curve from the frequency from the datasheet, the actual ESR is slightly less than 2 mOhms.Two tweezers showed a value of 2 mOhms at a frequency of 100 kHz, which is very cool.https://api.pim.na.industrial.panasonic.com/file_stream/main/fileversion/8713

author: iet
author_rank: Frequent Contributor
timestamp: November 27, 2024, 03:07:40 pm
content: In-circuit ESR measurement of the SP-Cap 220 uF capacitor.

author: iet
author_rank: Frequent Contributor
timestamp: December 01, 2024, 12:54:56 pm
content: I made new tips for the LCR P ro1 Plus tweezers. The same 1mm polished brass plate is used. The thickness of the tips for the Pro1 is 0.6mm. The tips are now more rigid and require less effort when measuring.

author: ranchero
author_rank: Contributor
timestamp: December 18, 2024, 12:54:14 am
content: From time to time I'm fixing broken car remotes. No available schematics of course, the only way to find out values - to have another key of same model and measure its components. Most important ranges - below 200nH and below 10pf (there are many components with such values in car fobs). Often they are in 0402 size which doesn't help either. So good LCR-meter with 100kHz range and stable readings is a must.I have DE-5000 and relatively expensive Chinese handheld tester (around $200 if I remember). They both produce comparable quite stable results with some tricks. Small values can't be tested in-circuit. Both units came with tweezers attachment, Chinese - with Kelvin clamps. However, for tiny components with tiny values the only good way to get stable readings - soldering them to small test board and insert board directly in meter, or (in case of DE-5000) - use TL-21 adapter (with very short 5cm cables and alligator clips). As I found - after proper calibration this works extremely well, I'm able to measure 1-2 pf capacitors with acceptable accuracy (even though stability of the measurement is more important for me).I'd love to have LCR tweezers, it would make measurements (at least bigger values) much more convenient, component and display within sight. But at $350 (LCR Pro1)...times are tough. Maybe someday. Cheap ones - I have feeling that they would be just waste of money.

author: mawyatt
author_rank: Super Contributor
timestamp: December 18, 2024, 02:56:27 am
content: Here's something we did, modified a TL-21 with BNC cables to allow DE-5000 use with standard LCR Meter Fixtures like the SMD Fixture shown. Good for small SMD values and no need to solder SMD component to a test board!!Edit: Here's a quick measurement of a precision 1pF C0G 0805 capacitor @ 100KHz, ref value (1.0104pF @ 100KHz) from Hioki IM3536 Lab LCR Meter. No tweaking the images, numbers, just a normal Open and Short DE-5000 with fixture attached by modified TL-21, then measurement.Best

author: ranchero
author_rank: Contributor
timestamp: December 18, 2024, 03:36:56 am
content: Something as simple as this works PERFECTLY. Just need to solder component to PCB. But I found that old components (desoldered from other key for example), nearly impossible to measure correctly unless it's soldered anyway.

author: iet
author_rank: Frequent Contributor
timestamp: December 19, 2024, 11:56:57 am
content: Quote from: ranchero on December 18, 2024, 12:54:14 amYou don't need to buy tweezers with a measurement frequency of 100 kHz. If the resolution of 0.1 uH and 0.1 pF is enough, then tweezers with a measurement frequency of 10 kHz-ST1 will do just fine. As a cheaper alternative to Pro1-LCR 1S. It has 100 kHz.

author: mawyatt
author_rank: Super Contributor
timestamp: December 19, 2024, 02:45:57 pm
content: Quote from: iet on December 19, 2024, 11:56:57 amYou do realize that a resolution of 0.1pF @ 10KHz requires the instrument to resolve the equivalent of achangein parallel Z of 160MΩ added to or removed from the DUT Z.Best

author: iet
author_rank: Frequent Contributor
timestamp: December 19, 2024, 08:19:23 pm
content: I see a resolution of 0.1 pF on the ST1 display. This is easily verified with the appropriate capacitors.rancherosaid in his message that he would like to measure capacitance below 10 pF. This could be 9,8.2, 4.7, 3.3, 2.2, 1.5, 1 pF or any other number. That is, he needs to measure pF units. And a resolution of 0.1 pF makes it possible to more accurately measure capacitors with tenths of a pF.

author: iet
author_rank: Frequent Contributor
timestamp: December 20, 2024, 09:02:03 pm
content: For general information - pF table. Test board. It is not finished yet. 0.1-100 pF.

author: ranchero
author_rank: Contributor
timestamp: December 20, 2024, 10:13:00 pm
content: Quote from: iet on December 19, 2024, 11:56:57 amSometimes there are inductors below 100nH. I need at least 10nH resolution.

author: iet
author_rank: Frequent Contributor
timestamp: December 20, 2024, 10:37:47 pm
content: Quote from: ranchero on December 20, 2024, 10:13:00 pmLook at this one.https://us.rs-online.com/product/rs-pro/1238652/71079735/?srsltid=AfmBOopYGS5zozDeYRiWmSTybav5aA94T27t9FyU2Juip0h9m5kMDOWj

author: iet
author_rank: Frequent Contributor
timestamp: December 20, 2024, 11:03:13 pm
content: Several measurements, as mentioned in message 76. Tweezers ST1-10 kHz.

author: iet
author_rank: Frequent Contributor
timestamp: January 03, 2025, 07:17:03 pm
content: Precision resistors 0.1% arrived. Soldered into the test board. Tweezers LCR Pro1 Plus.

author: iet
author_rank: Frequent Contributor
timestamp: January 08, 2025, 04:59:45 pm
content: Precision resistors 0.1%.

author: iet
author_rank: Frequent Contributor
timestamp: January 08, 2025, 11:01:15 pm
content: Precision resistor 0.05%.

author: iet
author_rank: Frequent Contributor
timestamp: January 14, 2025, 08:29:48 pm
content: Making a test board for testing leaded electrolytic and other types of capacitors took more time than other test boards.There are two sockets on the board. One is taken from an industrial board, the other is a well-known Zif socket. It turned out to be a very multifunctional and convenient thing.You can test capacitors with different lead thicknesses.You can test capacitors with different lead lengths.You can test capacitors with different distances between leads. The maximum distance is 40 mm.Good and reliable contact. The resistance between any contacts and test pins is 10 mOhms. That is, we will always subtract this value from the measurement result.The test pins are silver-plated, which ensures high-quality contact. They are well suited for all types of tips of different tweezers, ordinary multimeter probes and Kelvin clamps. If the pins wear out, they can be easily replaced.You can take measurements with two devices at the same time.The board has a connector for connecting a device for forming capacitors.It is also possible to measure leaded resistors.

author: iet
author_rank: Frequent Contributor
timestamp: January 15, 2025, 10:44:17 pm
content: For example, I measured the ESR of a 3900 uF capacitor, Low impedance series.18-10 = 8 mOhms.Now I can calmly start measuring the parameters of the capacitors and carefully place them in the appropriate box.

author: iet
author_rank: Frequent Contributor
timestamp: January 18, 2025, 07:20:47 pm
content: There are no problems with electrolytic capacitors. There are many of them and the results will need to be entered into a table. Moreover, it is better to group them by manufacturers. At the same time, separate regular and low-impedance capacitors. But with picofarad capacitors 0.1-1 pF it is more difficult. While I am waiting for the ordered 0.1 pF, I found another one for 0.47 pF. I measured with two tweezers. The obtained values ​​coincide and correspond to the accuracy and resolution of these tweezers. This is good.

author: iet
author_rank: Frequent Contributor
timestamp: January 19, 2025, 02:19:10 pm
content: Low impedance electrolytic capacitors of different series. Nippon Chemi-Con. Measured ESR with two tweezers. Pro1 Plus-100 kHz and ST1-10 kHz.ESR table.

author: iet
author_rank: Frequent Contributor
timestamp: February 25, 2025, 07:26:06 pm
content: While browsing the internet for information about the QPLINK 1S tweezers, I found a link to a review of these tweezers. It is easy to read using Google Translate.There are tables of L, C, R measurement results with three devices.Of what interests me, there is a measurement of 10 nH inductance. There are calibrations. There is no information on resistors in the milliohm range and on measuring the ESR of capacitors at a frequency of 100 kHz.Overall, the review is positive.But I haven't decided yet whether to order it or not to replace the MS8911 or FNIRSI ST1.Conclusions from the review.ConclusionsVery good tweezers, surprisingly accurately measure capacitances at a frequency of 1 kHz up to 100 uF. At 10-100 kHz the error is greater, but these are still operating modes. And these tweezers are definitely better than Fnirsi lcr st1.Pros:Resistances from 100 mOhm with a resolution of 1 mOhmAccurately measures resistance, accurately measures capacitance and inductance at a frequency of 1 kHzCalibration capabilityMeasures voltage normally and accurately after calibrationThere is a calibration board for self-assembly, there is a screwdriver for disassemblyGood battery capacity and adequate power consumptionClear display with wide viewing anglesAdequate and fast display rotation for right and left handFast dialing in 10-100Khz modeCons:Calibration is required to fully utilize the device's potential.Only resistors are soldered on the calibration board.The resistors on the calibration board need to be replaced.There is some instability of readings in the measurement mode due to temperature, frequency drift and ADC noise, however, this has little effect on accuracy.Diodes are tested only up to 1Vhttps://mysku.club/blog/aliexpress/102487.htmlIn the meantime, I am preparing to measure the ESR of capacitors at a frequency of 100 kHz.Finished a desktop ESR tweezers for 100 kHz with a large microammeter, 140x70 mm. Between tens of uA, ten divisions. Excellent sensitivity, good overview. Linear scale 1-500 mOhms.I already gave a link to the diagram in message 60. The board is from the first version of the tweezers. But for the first time I used Schottky diodes with Vf-0.1 v.Most of the time was spent on linearizing the scale, so I had to select some resistors. Highly stabilized power supply 3.7 v.Now the T2 tweezers with this scale will take part in measurements at a frequency of 100 kHz on a par with digital tweezers.

author: iet
author_rank: Frequent Contributor
timestamp: March 19, 2025, 07:06:59 pm
content: Measuring ESR of electrolytic capacitors at 100 kHz.

author: iet
author_rank: Frequent Contributor
timestamp: March 20, 2025, 12:27:03 am
content: Measuring ESR of electrolytic capacitors at 100 kHz.

author: iet
author_rank: Frequent Contributor
timestamp: April 22, 2025, 04:56:48 pm
content: Now it is possible to check the results of measurements of various components made by different LCR tweezers.Thanks to a lucky chance, I bought a UT622C LCR meter from a friend.https://unitrend.oss-cn-hongkong.aliyuncs.com/upload/file/20210615/UT622%20Datesheet.pdfI bought it a little cheaper and without Kelvin probes. Therefore, I decided to make Kelvin probes in the form of clamps and tweezers myself.Some things were bought, but most of the work had to be done myself.First, I made an adapter for BNC connectors.Then I made three types of measuring cables.1 4-wire Kelvin probes.2 4-wire Kelvin tweezers with two pairs of tips.3 Tweezers with a shielded two-wire cable.That is, I now have two sets of measuring cables for real 4-wire Kelvin measurements, for components with axial/radial leads and SMD components.

author: iet
author_rank: Frequent Contributor
timestamp: September 14, 2025, 07:30:42 am
content: New tweezers from FNIRSI LCR ST2.Frequency 100 kHz.Replaceable probes.Display rotation.

author: iet
author_rank: Frequent Contributor
timestamp: September 16, 2025, 08:02:26 pm
content: I watched several videos about ST2. Compared to ST1, the number of interesting functions has been increased.Sweep test frequencies.Simultaneous display of measurement results in serial and parallel mode.Measurement speed adjustment.Sorting.Voltage measurement.Sweep test frequencies.In automatic mode, you can track the parameters of R, L, C components at different frequencies. A very original technical solution that saves time when measuring.The range of test voltages has been expanded: 0.1 / 0.3 / 0.6 / 1V.0.1V to minimize the influence of semiconductor elements during in-circuit measurements. 1V for overall improvement of measurement accuracy, as well as for measuring ceramic capacitors.We can say a big thank you to FNIRSI for the frequency of 100 kHz. This completely solves the problem of measuring the ESR of different types of capacitors at this frequency, as well as the ranges of picofarads and nanohenries.It is noticeable that FNIRSI responded to the comments on the tweezers operation, especially in the diode/continuity mode. If so, then now it will be possible to search for short circuits in boards and components using the mOhms range and a resolution of 0.1 mOhms.And the most interesting news is the replaceable probes. An absolutely innovative solution, for the first time using Kelvin clamps and a connection scheme, actually up to the point of contact with the component. The changes affected both the tips themselves and their fastening, which is naturally very good.Thus, ST2 turns into a multifunctional tweezers, solving a wide range of problems in electronics.https://www.bilibili.com/video/BV125pEzNExE/

author: indman
author_rank: Super Contributor
timestamp: September 17, 2025, 08:23:07 am
content: Quote from: iet on September 16, 2025, 08:02:26 pmYes, yes, rush to buy this tweezers faster, it will replace you with all your measuring devices, including bench!I am afraid to suggest that Fnirsi will offer us in the next ST3 model - probably, the measurement frequency of 1 MHz and the possibility of non-contact measurements of the units by milliohm by WiFi!

author: Serg65536
author_rank: Regular Contributor
timestamp: September 18, 2025, 07:32:35 am
content: Zoyi just released MD2 tweezers. Very cheap, but capable!https://www.eevblog.com/forum/testgear/zoyi-zt-md2-100khz-lcr-bridge-tweezers-frequency-scan-voltage-diode-generator/

author: iet
author_rank: Frequent Contributor
timestamp: September 18, 2025, 07:49:00 pm
content: Quote from: Serg65536 on September 18, 2025, 07:32:35 amThey continue to try to move in sync, with the exception of minor differences.The ST2 tweezer have a redesigned tips. They are now completely smooth.They can be made of either polished brass or some other metal plated with gold.

author: iet
author_rank: Frequent Contributor
timestamp: September 19, 2025, 11:50:58 am
content: Frequency 100 kHz. Range nH. Measurement of short length wire. Inductance 20.1 nH.https://www.bilibili.com/video/BV1gPHZzpEXb/?spm_id_from=333.788.recommend_more_video.2

author: shabaz
author_rank: Frequent Contributor
timestamp: September 19, 2025, 03:03:58 pm
content: I don't understand what's being demonstrated in that photo. It looks meaningless (unknown wire, unknown comparison to any other source of information).Is it to demonstrate the accuracy? If so, then it would be better to use a known value inductor (e.g. a little air core inductor) and then compare the result to either the datasheet for the inductor, or at least some other known good test instrument.For instance, here is a22 nH air core inductor.Also, looking at the other values on that display, the jumper wire is very suspect, or no calibration was done, because the measurement shows quite a high resistance (would have expected it to be lower at what looks like a very short length although even that's chopped off the photo), but it's all a guess because everything in the photo is an unknown.

author: Grandchuck
author_rank: Super Contributor
timestamp: September 19, 2025, 03:39:10 pm
content: They range UP from 22nH

author: mawyatt
author_rank: Super Contributor
timestamp: September 19, 2025, 04:26:56 pm
content: The jumper wire looks to be about ~100mm in length, if even close this indicates the inductance reading of ~20.1nH is too low, should be much higher!!Best

author: iet
author_rank: Frequent Contributor
timestamp: September 20, 2025, 07:36:46 am
content: Quote from: shabaz on September 19, 2025, 03:03:58 pmThe presence of a nH range. The ST1 tweezers didn't have it. They used a piece of copper wire, apparently because there wasn't any inductance in that range. Naturally, it's difficult to talk about any accuracy.

author: iet
author_rank: Frequent Contributor
timestamp: September 20, 2025, 01:36:53 pm
content: Quote from: mawyatt on September 19, 2025, 04:26:56 pmYou've roughly estimated the length. What's the diameter? Perhaps I'll find some wire like that and measure it. To understand how the ST2 tweezers work in the nH range, you first need to buy it, calibrate it, and test it yourself.

author: mawyatt
author_rank: Super Contributor
timestamp: September 20, 2025, 02:43:23 pm
content: Quote from: iet on September 20, 2025, 01:36:53 pmFor rough thin wire inductance estimates it's wire length that dominates, a wire diameter of 0.5mm, or 1mm affects inductance by less than +-10% at ~ 100mm length. For thin long wires like shown a rough estimate is ~ 1nH/mm, so one wouldguessat something like ~ 100nH for a ~ 100mm 1mm wire, not 20nH as shown which would imply something like 20~25mm wire length!!We already know how these tweezers work, and the limitations of such, and certainly not going to invest in them (we already have quality bench LCR meters available for precision use (TH2830 and IM3536), good handheld (DER-5000), and a set of cheap tweezers (ZT-MD1) for ball park measurement use).A question: How are you going to "Calibrate" these tweezers in the nH range? Do you have access to aknown accuratenH level inductor?Best

author: shabaz
author_rank: Frequent Contributor
timestamp: September 20, 2025, 03:22:53 pm
content: Quote from: iet on September 20, 2025, 07:36:46 amIn the video, the displayed measurement fluctuated from about 15 to 21 nH.Can I ask who this would be useful for? I'm struggling to see how it helps anyone designing a circuit, because they will use known value parts (i.e. with datasheets), or measure at more precision, and/or measure at the frequency of interest (i.e. with a different instrument), or calculate, or make their circuit tuneable so they don't care about the precise inductance, and perhaps some other techniques from time to time.I can see that for reverse-engineering a circuit, or if you want to double-check you've got approximately the right part, then this very imprecise capability may be useful, but is that it? This seems of limited value if that is all it's good for (maybe if I were reverse-engineering frequently, or needing to roughly spot-check frequently, it would be a different story, but how many engineers do that?). What kinds of things do you (or could you) use this particular level of capabiliity for, that make this a worthwhile purchase for you?

author: indman
author_rank: Super Contributor
timestamp: September 20, 2025, 03:30:23 pm
content: shabaz,These cheap tweezers are toys designed for quick approximate QUALITATIVE assessment of the element under study. Anyone who thinks that they will replace more serious devices, which are designed for QUANTITATIVE and QUALITATIVE measurement, is very deeply mistaken. In addition, in unskilled hands, these cheap tweezers can do more harm than good. This is my opinion.

author: shabaz
author_rank: Frequent Contributor
timestamp: September 20, 2025, 03:46:20 pm
content: Quote from: indman on September 20, 2025, 03:30:23 pmTypo there, you mean qualitative of course, not quantitative. I'm wondering, is that ballpark (qualitative) nH measurement capability worth it, and what types of activities does@ietuse it for (or what do they plan to use it for?) that makes this level of performance worthwhile for them.

author: indman
author_rank: Super Contributor
timestamp: September 20, 2025, 03:49:30 pm
content: shabaz, yes, yes, you corrected me correctly and understood my thoughts, thank you.English is a bit difficult for me, sorry.I have edited my previous message.

author: mawyatt
author_rank: Super Contributor
timestamp: September 20, 2025, 03:51:14 pm
content: We have a set of cheap tweezers (MD-1) just to check if something is behaving as expected, not for any type ofreal measurementwhere theparameter valueis important.Best

author: indman
author_rank: Super Contributor
timestamp: September 20, 2025, 03:53:35 pm
content: Quote from: mawyatt on September 20, 2025, 03:51:14 pmYes, yes, you're right, for a quick and simple check, nothing more.

author: shabaz
author_rank: Frequent Contributor
timestamp: September 20, 2025, 04:29:22 pm
content: Quote from: mawyatt on September 20, 2025, 03:51:14 pmHi,Makes sense, I too have a very low-cost (maybe $20) LCR tool in the back of the drawer for the occasional quick checks.I see now that the instrument being discussed is possibly low-cost (I could only find ST1 pricing, not ST2, but maybe it's similar), I had mistakenly assumed it was a pricey instrument with poor nH level performance, making me question the point of that feature.

author: indman
author_rank: Super Contributor
timestamp: September 20, 2025, 04:36:51 pm
content: Quote from: shabaz on September 20, 2025, 04:29:22 pmI think that the ST2 will cost about 2 times more (about $40 or more) than the ST1 because it has a 100 kHz frequency and a 4-wire connection.Is this useful?

author: shabaz
author_rank: Frequent Contributor
timestamp: September 20, 2025, 06:45:37 pm
content: Maybe for others, sure, but just speaking for myself, no, I have no use for this instrument, because it doesn't gain me any benefit.For me I just have two scenarios,(a) quick ballpark qualitative-type scenarios, for which I already have a similar-priced (well, $20) instrument, so I have no need to improve on that, and(b) precision measurements, which take time, and are not all that frequent, and for which the speed/ease of picking up tweezers isn't all that compelling for me at least, because if I want precision then I will likely set up a testbed, and/or measure at a different frequency or at my choice of multiple frequencies anyway, none of which those tweezers will help with.

author: iet
author_rank: Frequent Contributor
timestamp: September 21, 2025, 03:33:58 pm
content: Quote from: mawyatt on September 20, 2025, 02:43:23 pmThanks for the info. I'll find that wire and measure it.And by calibration, I meant the tweezers' own calibration using the L parameter. I hope it's there. But the ST2 isn't available for purchase yet. When I get it, I'll check everything myself.I'm planning on making two test boards: one for coarse and one for fine calibration, we'll see.Another SNAKOL SK-BD2 tweezers has appeared. Chinese manufacturers are unstoppable. And the most interesting thing is that all this is happening almost simultaneously.

author: ychat
author_rank: Newbie
timestamp: September 21, 2025, 06:58:36 pm
content: Quote from: iet on September 21, 2025, 03:33:58 pmThese seem to be a rebranded Zoyi MD2. They already made a rebranded MD1.

author: iet
author_rank: Frequent Contributor
timestamp: September 22, 2025, 09:59:10 am
content: Quote from: ychat on September 21, 2025, 06:58:36 pmBesides simply copying them, they could add something of their own.For example, more information in diode mode. This makes it easier to find problems in semiconductor components.Add a DC mode.Improve stability in the mOhms and pF ranges.Also, make it detect diodes in auto mode.For starters, at least make it like the MASTECH MS8910 tweezers. It does a great job of detecting good/bad diodes in auto mode.In continuity mode, you can also add multiple ranges, like here.

author: iet
author_rank: Frequent Contributor
timestamp: September 25, 2025, 08:59:09 pm
content: The inductor test boards are currently being filled.The first board contains inductors with factory markings: 220 nH-10 uH.The second board contains SMD inductors, desoldered from different boards: 1 nH-1 uH. Measurements were taken with two devices with very similar characteristics: the LCR Pro1 Plus and the UT622C.For the UT622C, I made two 4-wire Kelvin tweezers. The first tweezers have a tip spacing of 0.4 mm. The second tweezers have a tip spacing of 0.25 mm.First use of the 4-wire Kelvin tweezers with an LCR meter.1 nH inductor.

author: mawyatt
author_rank: Super Contributor
timestamp: September 26, 2025, 01:45:09 am
content: Quote from: iet on September 25, 2025, 08:59:09 pmYou realize a 1nH inductor is the equivalent of a typical IC wire-bond of ~1mm in length!! At 100kHz this has a reactance of ~628uΩ, not sure how one is going to reliably measure such with tweezers of any kind?This level of measurement requires specialized fixtures and high quality LCR meters like shown here:https://www.eevblog.com/forum/projects/different-type-lcr-smd-fixture/msg5143233/#msg5143233Best

author: iet
author_rank: Frequent Contributor
timestamp: September 27, 2025, 07:02:39 pm
content: Quote from: mawyatt on September 26, 2025, 01:45:09 amI read your thread.What's the smallest SMD component size you can measure with your specialized fixtures?The LCR Pro1 Plus tweezers can measure SMD components of these minimum sizes.The meter has a pair of gold plated tips that can pick the SMD components with size down to 01005 (0.4mm x0.2mm). The parasitic parameters of its probes are small and very predictable thanks to its unique mechanicaldesign. It significantly reduces the probability of measurement errors related to setup (such as wires, probes,tips).I'm making an experimental test board.So far, so good.10 nH inductor.

author: mawyatt
author_rank: Super Contributor
timestamp: September 28, 2025, 01:26:59 pm
content: Edit: To answer your question, the smallest SMD we use is 0603.Some thingsyou need to think aboutwrt to tweezers and low Z measurements.Tweezers don't have "True at DUT Kelvin Measurements" since the Kelvin Termination is made at blade end at the tweezer body and not at or even near DUT connection. Because of this limitation the Zero Ω Calibration is relied upon the compensate for this built-in deficiency, however the Zero Ω Cal is highly dependent upon tweezers contact tip pressure. Now you have the Zero Ω compensation which is highly variable that is used to compensate the highly variable pressure influenced DUT contacts.How are you going to reliabiliy measure with tweezers a 1nH inductor at 100KHz with the limited DUT current available (tweezers have lower measurement current than bench meters, some quality bench meters use >100ma test current) and highly variable DUT contact resistance which is compensated by a variable Zero Ω Calibration?Kelvin clips (even the cheap ones) are much better than tweezers for low Z measurements. Even these superior Kelvin Clips have to be carefully Zero Ω Calibrated as shown wrt the 4 Force and Sense orientation of the High and Low side terminal connections.SMDevices bring another level of uncertainty to these measurements and even the special LCR Meter SMD fixtures which employ the horizontal "plungers" are limited. These have the Force and Sense leads terminated at the left and right plunger body some distance from the DUT contact tips. These plungers are massive compared to tweezer blades, but still introduce some additional uncertainty in low Z measurements and why we developed the mentioned Split-Kelvin Technique where the SMD DUT end solder terminations actually make the Force and Sense connections. This technique has shown good results with low Z components which is why it was developed.The parasitic DUT contact resistance is the worst for tweezers compared the Kelvin Clips, as it depends on highly variable contact pressure applied by hand and the Kelvin Terminations are far removed for the DUT contact and the Kelvin Technique can't even partially compensate for such like with Kelvin Clips!! You can coat the tweezers blades with gold, silver, platinum or whatever you want, that's not going to help as this is a built-in limitation of tweezers. Tweezers have a place for convenience of measurement, not for precision and especially not for precision low Z measurements.Seemsyou still don't grasp the basic fundamentalsof low Z measurements and what's involved in such and keep posting ridiculous images and claims of low Z tweezer measurements.BTW love the tweezer images of0.2065mΩ, 100nΩ (yesnano-ohms) resolutionAnd1.0715nHat 100KHz, that's 100fH (yesfemto-henries) resolutionBest

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 28, 2025, 01:39:06 pm
content: Quote from: iet on September 27, 2025, 07:02:39 pmI highly recommend reading Mike's statements and learning from them.To put it simply: Ignoring the lack of standards or calibration, your image of a 10nH inductor is off by 23.8%. That's not precision.You can measure any size SMD component with tweezers capable of gripping the component, but that doesn't mean you can do so with any reasonable level of accuracy. Maybe that reading is close of enough for your needs, and that's fine too. Sometimes a ballpark figure is all you need.Thanks,Josh

author: iet
author_rank: Frequent Contributor
timestamp: September 29, 2025, 08:37:30 am
content: Quote from: mawyatt on September 28, 2025, 01:26:59 pmHave you tried writing here?https://www.lcr-reader.com/And asking the questions you're interested in? They've been making digital tweezers for a long time and are seriously considering these issues. They have some great devices for comparing measurement results, like the HIOKI IM3536. They can very professionally and accurately answer many of your questions and allay some of your concerns.And at the end of the article, there's a very interesting conclusion.ConclusionSince the launch of the Smart Tweezers LCR-meter project in 2005, Siborg Systems has been at theforefront of innovation in the electronics industry. Recent advancements in accuracy (0.1%), testfrequency (up to 250 kHz), and measurement range (0.1 pF to 1 F) have established the LCR-Readerproduct line as a leader in precision electronic measurements.Traditionally, measuring extremely small capacitance and inductance values (below 1 pF and 10 nH)required expensive benchtop meters. Now, with the LCR-Reader MPA, R2, or R3 models, using theproposed Open and Short Calibration Boards, these measurements can be performed in under a minuteand at a fraction of the cost.https://www.lcr-reader.com/documents/NASA%202025%20Calibration%20Boards%20.pdf

author: tautech
author_rank: Super Contributor
timestamp: September 29, 2025, 09:10:52 am
content: Quote from: iet on September 29, 2025, 08:37:30 amMike has experience far beyond what you might imagine and vast knowledge of IC design at wafer level where every little thing matters and high precision measurements are part of daily design tasks.We can all learn much from this man.

author: mawyatt
author_rank: Super Contributor
timestamp: September 29, 2025, 03:18:26 pm
content: Quote from: iet on September 29, 2025, 08:37:30 amWhy would we want to write to lcr-reader.com? We don't have any questions for them or own their tweezers, altho their tweezers seem nice!!BTW we have the Hioki IM3536 and the Tonghui TH2830 (both acquired new) for precision LCR device measurements, and the standard and custom or modified fixtures for various components to assist in difficult device measurements. We don't rely on tweezers for precision work, only for theconvenience of usewhich is what they are intended for.Fixturing is a very important and often overlooked aspect of quality repeatable LCR measurements for various components, especially important for very Low and very High Z cases. Check what we have and others have done wrt to such (many threads scattered thru out), also note the fixtures from quality sources such as Hioki, Keysight, R&S and Tonghui which can be quite expensive!!Cost is a major obstacle for most individuals and small labs, and we fall into that category now retired. If you spend some time searching the many threads here on various LCR meters and fixtures you'll see that considerable effort has been expended in developing techniques, custom fixtures, and fixture modifications to address extracting quality repeatable LCR measurements at reasonable costs. The mentioned "Split-Kelvin SMD Fixture" and technique are a good example for Low Z SMD measurements. An interesting similar approach involved utilizing a $6 18650 battery resistance fixture from YAOREA (will require modifying the cable for BNC use). This fixture has coaxial probe connections for the Force and Sense connections and larger SMDs can be positioned between the coaxial probes and the Force Sense connections made on the SMD end solder terminals similar to the Split-Kelvin technique. We didn't modify the fixture cable but created an adapter for DMM use as shown here, a direct cable conversion would be better since it avoids an extra connection.https://www.eevblog.com/forum/testgear/any-more-in-depth-info-on-the-yr1035-battery-tester-milliohm-meter/msg5784723/#msg5784723Anyway, please spend some serious time studying how these LCR measurements are properly conducted, the impedance levels involved (very Low and very High Z), the instruments involved, how they work (with their limitations) and the fixturing required to achieve quality repeatable LCR measurements, then you'll begin to appreciate what's being discussed.Best

author: iet
author_rank: Frequent Contributor
timestamp: September 30, 2025, 07:43:07 pm
content: Quote from: mawyatt on September 29, 2025, 03:18:26 pmI'll definitely spend time on these things, but right now I'm more interested in using 4-wire Kelvin tweezers. They were invented a long time ago, over 10 years ago, but this area has somehow died out.https://www.testandmeasurementtips.com/kelvin-probes-low-resistance-measurements/Thanks

author: iet
author_rank: Frequent Contributor
timestamp: September 30, 2025, 07:49:27 pm
content: Quote from: KungFuJosh on September 28, 2025, 01:39:06 pmIt might be the inductor itself. It worked on the board for many years. I don't want to talk about accuracy now. I'm interested in how two devices measure inductance in the nH range.The other inductor is 10 nH.Thanks

author: indman
author_rank: Super Contributor
timestamp: September 30, 2025, 07:54:59 pm
content: Quote from: iet on September 30, 2025, 07:43:07 pmFour-wire clamps (Kelvin method) were invented by Lord Kelvin (William Thomson) in 1861.

author: mawyatt
author_rank: Super Contributor
timestamp: September 30, 2025, 08:39:51 pm
content: Quote from: iet on September 30, 2025, 07:49:27 pmTime out please!!You've been posting for some time about utilizing tweezers to make various mΩ and fractional mΩ, pF and fractional pF measurements , and fractional nH regions!! Your image results you've shown are nothing short of spectacular, delving into nΩ, aF, and fH regions of resolution with images showing 0.2065mΩ, #13 shows 8 series leaded 1pF caps at 0.1267pF and #16 shows 6 paralleled resistor/inductor SMD at 0.8621nH measured results!!Now all of suddenmeasurement accuracyisn't important!!Please enlighten us to what is important, and why. We are very curious how one can achieve these remarkable results with any kind of repeatability with any type LCR instrument??Best

author: mawyatt
author_rank: Super Contributor
timestamp: September 30, 2025, 09:05:53 pm
content: Quote from: iet on September 30, 2025, 07:49:27 pmThese tweezers or LCR meters don't measure inductance directly, actually they don't measure capacitance or resistance directly either!! They measure the voltage across the DUT and the voltage from a transimpedance amplifier which is configured as a "virtual ground" input for the Low side of the DUT. This technique forces the Low side ~0v and the transimpedance amplifier output voltage is the DUT current scaled by transimpedance "gain". These two voltages are "vectors" which are used to compute the desired display parameter(s).A 10nH inductor at 100KHz has an impedance of +j6.28mΩ, a 1pF capacitor has an impedance of -j1.59MΩ.Best

author: iet
author_rank: Frequent Contributor
timestamp: October 03, 2025, 09:37:33 pm
content: I measured the 0.47 pF capacitor again with the UT622C LCR meter from reply 29.The UT622C is performing quite well so far. The same can be said for the 4-tip tweezers themselves. In other words, both the UT622C and the tweezers are being tested simultaneously.I measured the resistance again with the UT622C LCR meter from reply 115.

author: Bad_Driver
author_rank: Frequent Contributor
timestamp: October 05, 2025, 06:05:36 pm
content: I stumbled across this long thread because, out of laziness for sorting SMD components, I got myself a cheap Zoyi tweezers. For real measurements, I have a Matrix 5200 LCR meter, which I use more than I ever expected and for which I only need better fixtures. For more advanced RF measurements beyond the 200 kHz of the 5200, I use my VNA (Siglent SVA 1032). There’s a suitable tool for every task; otherwise, we’d still be hammering everything. This thread can probably end here. I’m amazed at Mawyatt’s patience, repeatedly shedding light on things with profound expertise, but it feels a bit like “casting pearls before swine.”Mike, we’ve all learned a lot from your experience over the years. Just let him keep measuring fH and nOhms with his tweezers.

author: iet
author_rank: Frequent Contributor
timestamp: October 06, 2025, 08:45:42 pm
content: Now I can easily find the right SMD inductors with two LCR meters.Inductor 20 nH.

author: iet
author_rank: Frequent Contributor
timestamp: October 07, 2025, 06:24:02 pm
content: The first test board for the inductors is ready. I used inductors with markings on the case. Range: 220 nH-1 uH.