FNIRSI LCR-ST1 (Inexpensive LCR Tweezers) - Page 1
Forum section: electronics / testgear

author: Rooster Cogburn
author_rank: Regular Contributor
timestamp: August 09, 2024, 09:35:55 pm
content: Looks like there isn't a thread about these yet. 30EUR-ish LCR tweezers. Some more info on AliExpress / fnirsi.co. Can't find a review. They seem really neat, but knowing FNIRSI there are likely some bugs and issuesAnybody try these yet?1.Product Model: LCR-ST12.Capacitance range: 1pF-22mF3.Inductance range: 1μh-10H4.Resistance range: 10mΩ-10MΩ5.Diode: On voltage 0.7V6.Frequency test: 100Hz, 1kHz, 10KHz7.Level test: 0.3V, 0.6V RMS8.Parameter display: ESR, D value, Q value, Z value, X value9.Display: 1.14'' color screen10.Charging Interface: Type-C, 5V/A11.Power Supply: 250mAh lithium battery12.Auto recognition measurement: Support13.Replaceable tweezer head: Support14.Auto shutdown: Support15.Data hold: Support16.History record: Connect to PC to view and export17.Language: Chinese, English18.Size: 28×19×150mm19.Weight: 41g

author: Martin72
author_rank: Super Contributor
timestamp: August 09, 2024, 10:09:56 pm
content: The accuracy specifications correspond to the price....I would rather save up for an ST42 from Shannon, then you would have won several times over.For example, as far as support is concerned, you can completely forget that with "Fnirsi".

author: indman
author_rank: Super Contributor
timestamp: August 10, 2024, 07:40:47 am
content: Quote from: Rooster Cogburn on August 09, 2024, 09:35:55 pmThis product is almost similar to the same one from ZOYI ZT-MD1.https://www.eevblog.com/forum/testgear/zoyi-zt-md1-new-lcr-tweezers/msg5589285/#msg5589285It seems that Chinese friends will soon fill the market with devices that will compete with the famous MASTECH MS8911

author: Rooster Cogburn
author_rank: Regular Contributor
timestamp: August 10, 2024, 08:37:15 am
content: Quote from: Martin72 on August 09, 2024, 10:09:56 pmI would've also paid several times over. That's a device in a completely different price class.Quote from: Martin72 on August 09, 2024, 10:09:56 pmI know, hence me asking if anybody has tried these. Never know with FNIRSI if the firmware actually works. The Miniware tweezers seemed interested but they also seem to have software problems.Quote from: indman on August 10, 2024, 07:40:47 amYeah, could be a re-brand. Can't find the ZOYI ZT-MD1 for sale on AE, no reviews anywhere either.Quote from: indman on August 10, 2024, 07:40:47 amI can only find the MASTECH MS8910 for sale and that seems like a rather basic DMM, none of the LCR features.

author: tautech
author_rank: Super Contributor
timestamp: August 10, 2024, 08:45:28 am
content: Quote from: Rooster Cogburn on August 10, 2024, 08:37:15 amAnd completely different capability class.After nearly 2 decades of using SMD LCR tweezers I can vouch ST42 are currently incomparable for their cost.

author: indman
author_rank: Super Contributor
timestamp: August 10, 2024, 08:51:11 am
content: Quote from: Rooster Cogburn on August 10, 2024, 08:37:15 amMS8910 is a simple toy compared to MS8911!Quote from: tautech on August 10, 2024, 08:45:28 amThis is true, but sometimes very high precision is not required from the tool and you can use a simpler device, especially since the price of the LCR-ST1less than $30. Another question is whether this price is justified, we will only know when there is a full review of this model of tweezers.

author: indman
author_rank: Super Contributor
timestamp: August 10, 2024, 09:08:08 am
content: Brief user manual for those who want to know more about this product.

author: Kosmic
author_rank: Super Contributor
timestamp: August 10, 2024, 02:23:40 pm
content: I was curious and ordered one on ebay. Found a seller listing at 26$US with free shippingcan't really beat that price.

author: Kosmic
author_rank: Super Contributor
timestamp: August 10, 2024, 02:47:24 pm
content: Quote from: tautech on August 10, 2024, 08:45:28 amSincerely, since you are yourself selling the ST42, I think we need to take your comment with a big grain of salt

author: Rooster Cogburn
author_rank: Regular Contributor
timestamp: August 10, 2024, 02:50:47 pm
content: Quote from: Kosmic on August 10, 2024, 02:23:40 pmLet us know ;-)I don't need such a device often enough to spend three figures on a great one. For me the choice is between these and nothing. If they don't work well enough I keep rocking with nothing, that's fine, too.

author: csuhi17
author_rank: Frequent Contributor
timestamp: August 10, 2024, 06:16:54 pm
content: Quote from: Rooster Cogburn on August 10, 2024, 08:37:15 amNot just the software.it didn't want to calibrate itself properly for me after the update, it succeeded 1 out of 5.After 3-4 months it started to have a contact fault.first at the jack connector and then also at the tip.Random off during use.Its measurement accuracy depended on how I held it, how tight it was on the two legs, how much I pressed it together...approx. I sorted 800-1000 SMDs just with it, and it was destroyed.I hope for those who buy Fnirsi that they get a better quality one, unlike me.4 out of 7 is garbage...

author: indman
author_rank: Super Contributor
timestamp: August 11, 2024, 06:56:10 am
content: Quote from: csuhi17 on August 10, 2024, 06:16:54 pmI don't know how to write a proverb in English, which is in Russian."Ежики плакали,кололись,но продолжали жрать кактус..."That's about right, I think you'll get the point:"The hedgehogs cried,they're in pain from needles, but kept eating cactus..."

author: indman
author_rank: Super Contributor
timestamp: August 11, 2024, 07:42:40 am
content: Quote from: indman on August 10, 2024, 07:40:47 amI found some short videos here, maybe it will be usefulhttps://www.bilibili.com/video/BV1EW421R74X/?spm_id_from=333.788.recommend_more_video.0https://www.bilibili.com/video/BV1DT421k7Xr/?spm_id_from=333.788.recommend_more_video.5

author: Kosmic
author_rank: Super Contributor
timestamp: August 21, 2024, 09:37:12 pm
content: Quote from: Kosmic on August 10, 2024, 02:23:40 pmI received the package today.Come in a nice storage case with extra tips, manual and usb cable.Side by side with the MS8911The output at 0.6v 1kHzSome measurements (all done at 1kHz):SR720MS8911LCR-ST12nF 0.1%C: 2.0004 D: 0.00025C: 1.99 D: 0.000C 2.012nF / D 0.00401uF 0.5%C: 1.0001 D: 0.00031C: 1.000 D: 0.001C: 1.002 D: 0.0002500nF 0.5%C: 500.87 D: 0.00023C: 501.0 D: 0.000C: 503.4 D: 0.0040125nF 0.5%C: 125.31 D: 0.00018C: 125.0 D: 0.000C: 126.1 D: 0.00325nF 0.5 %C: 5.0054 D: 0.00024C: 5.00 D: 0.000C: 5.022 D: 0.0027160 pFC: 160.07 D: 0.00140C: 1.6 D: 0.001C: 164.0 D: 0.000210mHL: 9.4265 Q: 59.970L: 9.38 Q: 78.60L: 9.474 D: 0.014450mHL: 48.070 Q: 83.446L: 48.04 Q: 85.60L: 48.23 D: 0.0160100mHL: 95.425 Q: 82.799L: 95.3 Q: 83.33L: 95.77 D: 0.0160100Ohm 0.1%R: 100.32R: 100.3R: 100.41kOhm 0.1%R: 1.0002R: 1.001R: 1.00110kOhm 0.1%R: 9.995R: 10.00R: 9.934100kOhm 0.1%R: 99.925R: 100.0R: 99.931MOhm 0.1%R: 0.9983R: 1.001R: 1.00So overall I'm pretty satisfied. Measurement is fast, accuracy seem to be in specs, form factor is small and light and the screen is bright and easy to read.On the other hand, thesecondary parameters are always the same. Rs and D. There is no way to get, for example, Q when measuring inductors. Build quality seem to be low but has to be expected from a 30$ device. Ex, there is only 1 screw holding each the tips. Not sure if they are going to last.

author: Kosmic
author_rank: Super Contributor
timestamp: August 22, 2024, 12:36:46 am
content: Ok so, to get more secondary parameters, you need to store the values on the device (using hold) and then connect via USB to retreive the .csv fileEx of .cvs file you will find on the device:No.TypeLevel(Vrms)Frequency(Hz)Value(R nF uH V)Rs(R)QDZ(R)X(R)1C0.61000100.64684.0688388.64190.00261574.11631581.3212C0.6100010.083535.4682445.00960.002215713.259815783.69433C0.610001.028465.6831332.46640.003154824.6875154823.98444C0.610000.09713353.3528355.16820.00281180783.51191004.125

author: indman
author_rank: Super Contributor
timestamp: August 22, 2024, 07:16:30 am
content: Quote from: Kosmic on August 21, 2024, 09:37:12 pmIf this toy is positioned as a bridge meter, it should at least somewhat fulfill this purpose.Look at your table more closely - do you see what a huge difference there is in the secondary parameter D readings at 1kHz?!!! Why do you need such a resolution for this parameter of 4 digits after the dot, if he's grossly mistaken by the third digit? The MS8911 has a lower resolution of 3 digits and it more adequately shows a D value similar to the results in the SR720 instrument.I've already pointed out the incorrect D measuring on a similar ZOYI tweezers herehttps://www.eevblog.com/forum/testgear/zoyi-zt-md1-new-lcr-tweezers/msg5604897/#msg5604897I'll repeat my question here - If the secondary parameters Rs, D, Q can't be trusted, then they become a useless addition and can mislead you, right?

author: Aldo22
author_rank: Super Contributor
timestamp: August 22, 2024, 10:27:36 am
content: What would you see as the advantages of these LCR tweezers (Zoyi, Fnirsi...) over a transistor tester (e.g. GM328A with SMD pad)?Is it mainly about the handling?

author: indman
author_rank: Super Contributor
timestamp: August 22, 2024, 10:53:47 am
content: Quote from: Aldo22 on August 22, 2024, 10:27:36 amNo, it's mostly to do with the way these devices work!Tweezers work with sine signal and at different frequencies, transistor tester works at 1st frequency and only with rectangular signal!

author: Aldo22
author_rank: Super Contributor
timestamp: August 22, 2024, 11:44:29 am
content: Quote from: indman on August 22, 2024, 10:53:47 amThank you. I guess so, but what does that mean in practice?I assume that if the GM328A shows me 20pF, the tweezer will also show me 20pF etc.?You say yourself that the secondary parameters can't be trusted. In-circuit measurements are apparently also questionable.So what practical difference is there between these cheap devices?As a beginner/hobbyist, I wonder whether such a device would be of any benefit to me.

author: indman
author_rank: Super Contributor
timestamp: August 22, 2024, 11:54:52 am
content: Quote from: Aldo22 on August 22, 2024, 11:44:29 amDespite my criticism, a tweezer or a device that works as a bridge meter will give you much more convenience and advantages than a transistor tester. Do not forget that this tweezer is positioned as an full-fledged LCR meter, the capabilities of the transistor tester are very limited in terms of measuring these values, as they are in fact only a bonus application to the abilities of this project. For example, can you reliably measure a 1pF capacitance on a tranzistor tester? Yes, Karl-Heinz has a great resonant method of such measurements, but it is only an exception to the rule.

author: Aldo22
author_rank: Super Contributor
timestamp: August 22, 2024, 04:27:20 pm
content: Quote from: indman on August 22, 2024, 11:54:52 amOK, if you say so....Ordered one. The price is good.

author: Evi
author_rank: Regular Contributor
timestamp: August 25, 2024, 03:42:14 pm
content: Anybody understand calibration prcedure?This idiotic video explains nothing.

author: UniSoft
author_rank: Frequent Contributor
timestamp: August 26, 2024, 04:41:14 pm
content: MCU: ARTERY AT32F403ACGU7LCD: N114-2413THBIG01-H13

author: NikNik
author_rank: Newbie
timestamp: August 31, 2024, 08:48:57 am
content: New firmware v1.5https://www.fnirsi.com/cdn/shop/files/LCR-ST1-V1.5.bin?v=1031665107150577539https://www.fnirsi.com/pages/download-firmwareI did not find any information about the changes, probably the changes are aimed at improving the accuracy of measurements...I did not see any changes in the work+ He started to display the polarity of the diodeby turning the icon

author: Phil1977
author_rank: Frequent Contributor
timestamp: August 31, 2024, 09:24:03 am
content: Quote from: UniSoft on August 26, 2024, 04:41:14 pmThanks for the pictures!One question: I´ve quite frequently seen quite highly priced semiconductors in these super cheap instruments. Like the INA 826 (usually around €3,- from authorized sources) in this case or sometimes even a €8 photomos-switch in a €10 DMM.I think even FNIRSI has too much reputation to loose to just use fake chips without any quality control. Do you thinka) Fnirsi uses originals from TI, even if these two chips alone would be one of the largest item in the BOMb) there is a spot market for such chips, Fnirsi just produces as long as they get cheap componentsc) they use fakes but good onesd) they use bad fakese) anything else???Quote from: NikNik on August 31, 2024, 08:48:57 amDo you know about any changelog?

author: NikNik
author_rank: Newbie
timestamp: August 31, 2024, 10:49:46 am
content: Quote from: Phil1977 on August 31, 2024, 09:24:03 amI did not find any information about the changes, probably the changes are aimed at improving the accuracy of measurements...I did not see any changes in the work+He started to display the polarity of the diodeby turning the icon

author: NikNik
author_rank: Newbie
timestamp: August 31, 2024, 08:09:52 pm
content: Possible problem and its solution..I encountered a problem, turned on the device, the line break does not show, the data jumps chaotically, when trying to measure, the readings are unstable, and only when pressing hard does something work more or less reliably, I press even harder, and the readings start jumping again.I soldered everything on the board that could cause problems.As it turned out, the problem is in the tips themselves, (in the upper one)...I drilled a larger hole to center the tips, the hole itself and the base of the probes for insulation (tip) covered with UV nail polish))the problem is that the installation pin itself shorts to some conductor, as a result of which the measurement mode is disrupted..after eliminating the problem, the device works stably..

author: lownoise
author_rank: Contributor
timestamp: August 31, 2024, 08:58:15 pm
content: The installation pin could probably be part of a 4-wire measurement, this would be good news for such a cheap device

author: NikNik
author_rank: Newbie
timestamp: August 31, 2024, 10:55:05 pm
content: Quote from: lownoise on August 31, 2024, 08:58:15 pmI don't think that's true because the defect appeared when the tip of the probe touched the pin. You can see the insulation around the pin... but it still touched some conductor inside the probe.. I didn't take it apart... I thought if that doesn't solve the problem I'll ask for a replacement..It's some kind of manufacturing defect.

author: Phil1977
author_rank: Frequent Contributor
timestamp: September 01, 2024, 06:24:57 am
content: Quote from: NikNik on August 31, 2024, 10:55:05 pmPlease teardown you unit if your seller does not want the defect device to be returned!I´ve just opened up my ST1 to find out about the tweezer tip connections. Unfortunately I couldn't remove the tweezer sleeves because I didn't want to de-solder them from the mainboard - at least as long as my ST1 is such a nice useful device for super quick identification of SMT parts.The only thing I could find out is that there are 4 solder connections per side of the tweezer going to the main PCB. One of these connections is directly connected with the tip, none of them seems to be directly connected to the dowel pin.Does someone know of a teardown where the housing of the tweezer PCBs was removed?

author: S2084
author_rank: Regular Contributor
timestamp: September 01, 2024, 08:59:34 am
content: I looked at the spectrum of the test sinusoidal signal at all available frequencies (100, 1000, 10000 Hz)

author: TD-er
author_rank: Newbie
timestamp: October 15, 2024, 08:02:14 pm
content: I just received my LCR-ST1.I suspect the internal battery is DoA, as it only allows me to run for 10 seconds. As soon as you disconnect the USB cable, the "full battery" indicator turns red and you see a pop-up countdown to shutdown.It only draws 7 mA when "charging", which it has been for hours now.The firmware update ZIP file does have a change-log file in the zip:QuoteSo far, as long as the USB cable is connected (and connected to some USB hub or power supply), the measurements do seem quite plausibleI do have one of those "resistor/capacitor calibration boards" from Ali.There are hand-written values on the white silkscreen, suggesting the parts are measured with some calibrated meter.However the values I measure with this tweezer are quite similar with the written down values and a few I compared with a few other meters I have. (none with "official" calibration certificates)I just bought this 'test board' to quickly test to see if my meters agree with eachother when in doubt.

author: DaneLaw
author_rank: Frequent Contributor
timestamp: October 15, 2024, 10:26:49 pm
content: Quote from: TD-er on October 15, 2024, 08:02:14 pmOpen it up and check the cell.If I recall its just a standard of the self 250mAh LIPO they are using.JHCY502030Its around 3€ from EU resellers, but if it arrived defect..and you have a chance to return it... then do that..

author: TheDefpom
author_rank: Frequent Contributor
timestamp: October 16, 2024, 09:08:56 pm
content: I thought I should post my review of them here...

author: TD-er
author_rank: Newbie
timestamp: October 18, 2024, 08:08:05 am
content: Quote from: DaneLaw on October 15, 2024, 10:26:49 pmI have no chance to return itEven better, Eleshop did send me a new one and I didn't have to return the old one.It arrived yesterday and immediately you can see it does charge at 200-ish mA and after like half an hour it already stopped charging, so it was like 80% full I guess.Works perfectly fine.I will have a look at the defective one and when opened I will take some pictures for whomever also experiences the same issue, or when this battery is eventually dead in like 3 - 5 years.