Why some brands don't do LCR meters? - Page 1
Forum section: electronics / testgear

author: pope
author_rank: Frequent Contributor
timestamp: November 30, 2023, 02:56:02 pm
content: Like Siglent or Rigol for example?Not big enough market?I could really do with a LCR meter with scanner card and data logger software that doesn't cost a fortune

author: HKJ
author_rank: Super Contributor
timestamp: November 30, 2023, 03:19:08 pm
content: Quote from: pope on November 30, 2023, 02:56:02 pmI have not heard about a LCR meter with a scanner card, it would also be rather complicated because the connections from the meter internals to the DUT has to be controlled.For logging TestController supports a few LCR meters and it is free.EEVBlog thread:https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/Download:https://lygte-info.dk/project/TestControllerIntro%20UK.html(Bottom of page)

author: alm
author_rank: Super Contributor
timestamp: November 30, 2023, 03:26:24 pm
content: It seems LCR meters are quite specialized, with some of the big manufacuters like Wayne-Kerr and IET not making other general test equipment like DMMs, function generators or scopes. So I guess the overlap in technology between LCR meters and other basic test instruments is quite limited.For a scanner, I would use an external multiplexer like those made by Keithley (7001) and HP/Agilent/Keysight. But performance might be a bit degraded, especially at higher frequencies.

author: themadhippy
author_rank: Super Contributor
timestamp: November 30, 2023, 03:46:14 pm
content: why dont aston martin do a van or why dont kfc do a turkey burger ?very similar to there main market but different enough not to fit in with there business model

author: pope
author_rank: Frequent Contributor
timestamp: November 30, 2023, 04:30:37 pm
content: Quote from: HKJ on November 30, 2023, 03:19:08 pmWell, my requirements are rather simple but I don't know where to look for.I make a lot of multi-tap audio transformers and inductors and I'm trying to find a way to measure their values (and ideally log them) without connecting and disconnecting all the time.So, in the case of a multi-tap inductor, one end of the LCR would connect to the first pin of the coil and the scanner would connect to the remaining pins, if that makes sense...Here'sa similar set-up

author: Kleinstein
author_rank: Super Contributor
timestamp: November 30, 2023, 06:09:11 pm
content: For a transformer the inductance is not such an important property. The inductance depends on the drive level and such nonlinear effects are what may be interesting for audio. One may be better off with some more general audio test system and a suitable amplifier to drive the transformer.The number of turns is one of the properties that usually has very little drift - so not that much need to log multiple taps over a longer time.

author: KungFuJosh
author_rank: Super Contributor
timestamp: November 30, 2023, 06:20:40 pm
content: For guitar pickups, inductance is one of the most important bits of info for determining output level. For them you also need at least 100kHz to test capacitance. Lower impedance pickups would need significantly higher frequencies available to properly test.

author: pope
author_rank: Frequent Contributor
timestamp: November 30, 2023, 06:25:08 pm
content: Yeah well my main concern is the multi-tap inductors. I make a lot and I need to match them so I've been looking for a faster/ better solution than measuring mnualy every single pin, writing it down and then trying to match them. It takes forever.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: November 30, 2023, 07:36:45 pm
content: GWInstek does some-https://www.gwinstek.com/en-US/products/layer/LCR_Meters

author: KungFuJosh
author_rank: Super Contributor
timestamp: November 30, 2023, 07:41:09 pm
content: Quote from: Conrad Hoffman on November 30, 2023, 07:36:45 pmTheir good LCR meters are the most expensive ones I've seen available commercially.TongHui, SourceTronic, Hioki, are all high quality at a much lower budget (NOT cheap tho).East Tester makes okay quality at mostly cheaper prices.

author: pope
author_rank: Frequent Contributor
timestamp: November 30, 2023, 08:16:18 pm
content: Matrix also seem to have some decent LCR meters.However, none of these meters address my needs AFAIK.

author: coromonadalix
author_rank: Super Contributor
timestamp: November 30, 2023, 08:20:21 pm
content: just a matter of building a test rig for the xformers wiring, controle them as the same time you control your lcr to poll measurements, once a day you do zero cal open and or closedwith some small mcu like arduino relays etc ... anything is possible if you want to bin parts

author: Stray Electron
author_rank: Super Contributor
timestamp: November 30, 2023, 08:36:50 pm
content: My guess is that all of the added wiring associated with all of the additional DUT (Device Under Test) circuits with a scanner card for multiple DUTs would play hell with the accuracy of an LC meter. Resistance meters can compensate for added wiring by using a 4 wire Kelvin connection but I don't think that that is realistically possible on an LC meter when testing multiple DUTs.

author: KungFuJosh
author_rank: Super Contributor
timestamp: November 30, 2023, 08:48:59 pm
content: Quote from: pope on November 30, 2023, 08:16:18 pmThe Matrix units I've seen were mostly knock-offs or rebrands of others.In general, to get the best results with an LCR, you need to limit anything between the meter and the DUT. Cables have to be compensated properly, etc.

author: tszaboo
author_rank: Super Contributor
timestamp: November 30, 2023, 09:21:20 pm
content: I would measure the inductance end to end, then connect a 1khz (for example) AC on one tap and measure the rms voltage on all the other taps. That is easy to multiplex, compared to what you have in mind.

author: pope
author_rank: Frequent Contributor
timestamp: November 30, 2023, 09:31:19 pm
content: Thank you gents.We're talking about a range from 10-20mH to 10H maximum and accuracy of less than 5% is more than enough so, perhaps wiring Vs accuracy is not an issue in such scenario(?)

author: tszaboo
author_rank: Super Contributor
timestamp: November 30, 2023, 09:43:14 pm
content: Quote from: pope on November 30, 2023, 09:31:19 pmI'm confused. Are you making random inductors and need to verify their specifications? Or are you making the same inductor over and over again, and you need to verify?Because if the latter, then count the turns ratio?

author: pope
author_rank: Frequent Contributor
timestamp: November 30, 2023, 09:52:35 pm
content: Quote from: tszaboo on November 30, 2023, 09:43:14 pmI make multi-tap inductors with the same values and I want to match them in pairs. The closest they're matched the better.So, for example each inductor has 11 taps ranging from 10mH all the way up to 10H.Does it make sense?

author: BeBuLamar
author_rank: Super Contributor
timestamp: November 30, 2023, 11:53:52 pm
content: I don't know why either for example Fluke doesn't sell LCR meter but the Amprobe division does.

author: TimFox
author_rank: Super Contributor
timestamp: December 01, 2023, 12:11:19 am
content: Fluke did make an LCR meter back in 1996: The PM6306.https://dam-assets.fluke.com/s3fs-public/PM6306__umeng0200.pdf

author: pope
author_rank: Frequent Contributor
timestamp: December 01, 2023, 11:55:58 am
content: After a bit more digging I found out that apparently such devices do exist and they're called "Automatic Transformer Testers" but they are rather expensive and almost impossible to find them in EU or in the West in general...here's n example

author: Martin72
author_rank: Super Contributor
timestamp: December 01, 2023, 11:58:59 am
content: You can buy a transformer tester from sourcetronic:https://www.sourcetronic.com/shop/de/transformatorentester-st2829ax.html

author: alm
author_rank: Super Contributor
timestamp: December 01, 2023, 12:08:59 pm
content: Wayne Kerr is a western brand that makes magnetics analyzers, but you may not like the price. You will probably need to provide your own switching between windings, though.

author: HKJ
author_rank: Super Contributor
timestamp: December 01, 2023, 12:47:14 pm
content: Quote from: pope on November 30, 2023, 04:30:37 pmYou could build a computer controlled relay box and then do it from TestController. There is a project herehttps://lygte-info.dk/project/LogicOutputs%20UK.htmlfor digital output that works with testController. Relace the optocopler with relays and you have a relay box. The project is nothing more than a Arduino driving the relays.

author: pope
author_rank: Frequent Contributor
timestamp: December 01, 2023, 01:21:56 pm
content: thank you guys.Martin, that's a bit beyond my budget and quite frankly overkill for my needs but thank you very much indeed for the recommendationHKJ:I'm into analog electronics and last time I did something digital was when Arduino was first launched some 20 years agoHaving said that, I'm quite confident that I can find my way into making something like this. Thank you for the link? Looks very interesting.So, if I'm not mistaken, all I need is to build the suggested arduino project and some LCR meter that is being supported by testController like the East Tester ones?The idea is to automatically switch through the various pins, log the data and then I need to find a way to exprt the data into excel where the matching would be take place.At least that's what I'm hoping for...

author: HKJ
author_rank: Super Contributor
timestamp: December 01, 2023, 01:31:10 pm
content: Quote from: pope on December 01, 2023, 01:21:56 pmThat is correct and TC can easily export to Excel (It exports in CSV or TAB format and can use either , or . as decimal point).TC can run scripts and selecting a relay, waiting a bit, log a value and do that for a couple of values is easy to do (I can help if necessary).

author: pope
author_rank: Frequent Contributor
timestamp: December 01, 2023, 01:56:18 pm
content: Quote from: HKJ on December 01, 2023, 01:31:10 pmThank you, much appreciated.

author: AVGresponding
author_rank: Super Contributor
timestamp: December 01, 2023, 04:22:18 pm
content: Quote from: TimFox on December 01, 2023, 12:11:19 amTechnically that's a rebranded Philips...

author: alm
author_rank: Super Contributor
timestamp: December 01, 2023, 04:31:40 pm
content: I think there's also a Fluke / Philips LCR meter that looks identical to a Wayne Kerr model.

author: KungFuJosh
author_rank: Super Contributor
timestamp: December 01, 2023, 06:17:09 pm
content: Quote from: Martin72 on December 01, 2023, 11:58:59 amAnother rebranded TongHui unit. Obviously prefer SourceTronic for support though. 😉

author: Martin72
author_rank: Super Contributor
timestamp: December 01, 2023, 09:36:52 pm
content: That can only speak for Tonghui in terms of quality.

author: MathWizard
author_rank: Super Contributor
timestamp: December 02, 2023, 11:57:52 pm
content: You know how there's the FY6900 100MHz Signal generator, it's even in a case like big name versions.Does any body make cheap LCR or Impedance analyzer versions up to even 50MHz, that are in a box, and are not $20 ebay sig gen or LCR tester quality, but upto the FY6900 level ?For hobby RF projects, I would want to test a part, at the intended frequency, or close to it, quicker than using a scope and AWG, etc. Or sweep the frequency too and get a plot of something, and even upload it to PC.

author: Kosmic
author_rank: Super Contributor
timestamp: December 03, 2023, 12:05:16 am
content: Quote from: MathWizard on December 02, 2023, 11:57:52 pmThe NanoVNA ? LCR meters rarely exceed 1Mhz. Normally with higher frequencies, people switch to a VNA.

author: MathWizard
author_rank: Super Contributor
timestamp: December 03, 2023, 12:14:57 am
content: I have my eye on them too, I wish they were in a box. So they are a VNA, I have to research all this more because I can't remember if the NanoVNA needs an external signal source, or if it makes it's own. I'm pretty sure good SA's and VNA's have a good SG inside too.I better look up Impedance analyzer's for sale and read their spec's, see what they do.As a bench LCR meter, I wonder if something like this really has the mili-ohm spec's listed. I'd like something like these too, IF you could set the frequency to anything you wanted up to the max 100kHz. But yeah I want upto AM radio range at least.https://www.banggood.com/Mustool-ET4410-Series-Desktop-Digital-LCR-Meter-Capacitance-Resistance-Impedance-Inductance-Measure-LCR-Bridge-LCR-Meter-p-1984698.html?utm_source=googleshopping&utm_medium=cpc_organic&gmcCountry=CA&utm_content=minha&utm_campaign=aceng-pmax-ca-en-pc&currency=CAD&cur_warehouse=CN&createTmp=1&utm_source=googleshopping&utm_medium=cpc_all&utm_content=nolan&utm_campaign=nolan-aceng-pmax-ca-all-230818&ad_id=&gclid=EAIaIQobChMI6_ve3f7xggMVmOnICh08MgK0EAQYBCABEgIQAfD_BwE

author: Kosmic
author_rank: Super Contributor
timestamp: December 03, 2023, 12:17:00 am
content: Quote from: MathWizard on December 03, 2023, 12:14:57 amNo, it's self contain. You can even get one of those cheap adapter board to quickly put different components in different configurations.

author: alm
author_rank: Super Contributor
timestamp: December 03, 2023, 12:21:30 am
content: In addition to the NanoVNA, also read up on the LiteVNA. I believe it's a bit higher performance and more stable (based on what joeqsmith wrote in the past), but also a bit more expensive than the NanoVNA.

author: MathWizard
author_rank: Super Contributor
timestamp: December 03, 2023, 12:31:31 am
content: Yeah I have to get one, I don't need a Siglent SSA3021X+ yet, but I'm watching those too. Later this month I should get a Nano/version, from the legit sellers, not a clone.For sub 50MHz stuff, and I stick to ebay/amazon level prices, about how much money would all the accessories cost for a Nano, and to hook up to the DUT , and make little test jig's or whatever ? Sometimes I see splitters used so your scope can be hooked up too. I know this stuff can add up real quickly.

author: Kosmic
author_rank: Super Contributor
timestamp: December 03, 2023, 01:00:30 am
content: The little board on the picture I posted is normally 5$US (with all connectors and stand).

author: pope
author_rank: Frequent Contributor
timestamp: December 03, 2023, 11:25:29 am
content: I just pulled the trigger on a ET4510.We shall see...

author: pdenisowski
author_rank: Super Contributor
timestamp: December 04, 2023, 11:34:55 am
content: Quote from: Kosmic on December 03, 2023, 12:05:16 amThe R&S LCX goes up to 10 MHzhttps://www.rohde-schwarz.com/us/products/test-and-measurement/lcr-meters-and-impedance-analyzers/rs-lcx-lcr-meter_63493-1172288.htmlThe "LCR Meter vs VNA" question comes up often enough that we created a web page to help people decide (since we make both types of instruments)https://www.rohde-schwarz.com/uk/products/test-and-measurement/essentials-test-equipment/dc-power-supplies/lcr-meter-vs-vna_256867.html

author: KungFuJosh
author_rank: Super Contributor
timestamp: December 05, 2023, 05:15:34 am
content: Quote from: Kosmic on December 03, 2023, 12:05:16 amNah, that depends on who you're talking about- hobbyists, yeah. High freq LCRs are expensive AF. Many components are often tested with LCRs at higher frequencies.Quote from: pdenisowski on December 04, 2023, 11:34:55 amGreat, another $20,000 LCR I need to save up for. 😉

author: tszaboo
author_rank: Super Contributor
timestamp: December 05, 2023, 05:12:24 pm
content: Quote from: KungFuJosh on December 05, 2023, 05:15:34 amSo is it time to make the NanoLRC, with a 4 inch screen and random specifications. Like having a part and making the specifications for that rather than the other way around?

author: KungFuJosh
author_rank: Super Contributor
timestamp: December 05, 2023, 05:52:15 pm
content: Quote from: tszaboo on December 05, 2023, 05:12:24 pmI love the idea of a NanoLRC. It can live in the drawer with my TinySA Ultra.I'm not sure what you're inferring from your second statement? Parts I was referring to being tested in higher frequencies are done that way because they need to be. The accuracy range of lower frequency LCR meters (even up to 200kHz) is quite limited. You can see this by looking at the accuracy reference charts that come with any respectable LCR.

author: TimFox
author_rank: Super Contributor
timestamp: December 05, 2023, 06:05:26 pm
content: Why do you say that the accuracy of lower-frequency LCR meters is limited?Even an inexpensive DE-5000 achieves 0.3% (+2 digits) over much of its range at 100 and 1000 Hz for capacitance.Seehttps://www.deree.com.tw/de-5000-lcr-meter.htmlfor full specifications.

author: KungFuJosh
author_rank: Super Contributor
timestamp: December 05, 2023, 06:13:04 pm
content: Quote from: TimFox on December 05, 2023, 06:05:26 pmThat's not how it works. Switch to the tab that says specifications. For example, DCR is limited from 200Ω to 200MΩ with 1.0%+3 to 2%+3 accuracy respectively, and the sweet spot of .2%+2 between 2kΩ to 20kΩ. That's all low accuracy compared to lab grade LCR meters.Here's the accuracy chart of my bench LCR:The center box is the highest accuracy range. The farther out you go from there, the worse the accuracy gets (worst case on the chart still better than what the DE-5000 can do).

author: TimFox
author_rank: Super Contributor
timestamp: December 05, 2023, 06:22:53 pm
content: Yes, there are limits to specified accuracy, just like any other measurement device.Note that the DE-5000 costs roughly $140 US.You can obviously obtain higher accuracy for more money.I tried to link to the Specifications tab, but the result linked to the overall page with access to the Specifications tab, from which I excerpted some values and suggested that the interested reader look at the full specifications.Before I retired, I used a QuadTech (now IET) 1920 LCR meter at work, which has better specifications and higher test frequencies (0.1% accuracy at sweet-spot settings, 1 MHz max frequency).The current price is roughly $5500 (depending on options)https://www.ietlabs.com/1900-lcr-meter.html

author: KungFuJosh
author_rank: Super Contributor
timestamp: December 05, 2023, 06:36:11 pm
content: Quote from: TimFox on December 05, 2023, 06:22:53 pmRight. That was my point; better accuracy and general usefulness requires a broader frequency range, and costs more. The DE-5000 is very limited, but also very good for its price.

author: alm
author_rank: Super Contributor
timestamp: December 05, 2023, 07:21:41 pm
content: Quote from: KungFuJosh on December 05, 2023, 06:36:11 pmWhy do you think accuracy and frequency range are linked? Counter point: theGR 1620 bridgewith extremely high accuracy but a very limited frequency range. Best accuracy is achieved at 1 kHz.I won't argue that a wider frequency range is more versatile, but for ultimate accuracy a1 kHz-only bridgemight be better.

author: Kosmic
author_rank: Super Contributor
timestamp: December 05, 2023, 07:25:31 pm
content: Quote from: KungFuJosh on December 05, 2023, 06:36:11 pmIs there really a link between frequency range and accuracy ?This is the accuracy of the R&S LCX pdenisowski linked just above:at 10KHz you are already at 0.1% and 10MHz you are at 1%.I think they are just better instruments thus more expensive. And more expensive instrument have more features like extended frequency range.

author: KungFuJosh
author_rank: Super Contributor
timestamp: December 05, 2023, 07:58:22 pm
content: Quote from: alm on December 05, 2023, 07:21:41 pmYour counterpoint isn't a counterpoint, it is my point. I'm talking about accuracy across a broader range of component values, not specifically high accuracy within a limited range of values. All meters have a higher accuracy in a specific frequency range.Quote from: Kosmic on December 05, 2023, 07:25:31 pmYou're ignoring component value, and focusing only on the frequency. Any component value that falls outside of those ideal boxed ranges is questionable at best. By that chart, even the 10MHz upgrade ($20k), is mediocre accuracy to measure 100pH. I'm not aware of there being a 20MHz upgrade for that range, but that would be required to measure that.Compare it with Instek's 8200 series accuracy chart:Accuracy still drops off, but the ability to test AT ALL is better than nothing.

author: TimFox
author_rank: Super Contributor
timestamp: December 05, 2023, 08:19:22 pm
content: Another single-frequency instrument with excellent accuracy (at that frequency) is my venerable Wayne-Kerr B221 admittance bridge, which uses a ratio-transformer bridge to compare the unknown admittance (parallel-equivalent capacitance and conductance) to two (each) fixed resistors and capacitors at 1592 Hz (10,000 rad/sec).The calibration, even after 50 years, is quite good, due to hermetically-sealed standards and the constancy of integer turns numbers.See page 10 ofhttps://www.pa3esy.nl/meetinstrumenten/wayne-kerr/pdf/Wayne%20Kerr%20Universal%20Bridge%20B221%20and%20accesories.pdffor accuracy specifications, including the range of values for 0.1% accuracy.The coolest part of this well-designed instrument is the null indication for the bridge: two cascaded dual magic-eye tubes, which form a wide dynamic range null indicator with negligible delay, for easy nulling.Due to the ratio-transformers, negative capacitance (from parallel inductance) and admittance (when necessary) can be measured, and a table of reciprocals in the manual makes it easy to compute the inductance from a negative capacitance value at 1592 Hz to better than slide-rule accuracy.The exact frequency is only necessary for inductance calculations: the capacitance and admittance only depend on the standard components.Another of my good bridges is a General Radio "Z-Y" bridge, usable from 20 Hz to 20 kHz, capable of measuring any impedance/admittance.(The G-R 1620A is no longer in production at IET, but is good down to 0.01%.)

author: Kleinstein
author_rank: Super Contributor
timestamp: December 05, 2023, 10:14:17 pm
content: With some parts the frequency for the measurement can matter. This are especially capacitors / inductors that are not ideal but have loss (e.g. electrolytics, X7R). This makes the capacity / inductance frequency dependent.A larger frequency range can improve and the measurement range, but not directly improves accuracy. It is more that a limited frequency range / single frequency may allow for better accuracy in the range that works well (not too large or small). The old style bridges were often fixed frequency and can still be very accurate.A frequency range can still be handy, but the higher frequencyies are somewhat limited: the parts may no longer behave like a simple inductor / resistor or capacitor but one would need a equivalent circuit with more parameters to measure. So one may need more the a LCR meter, but an impedance analyzer as a more general instrument.