New LCR meters, Zoyi ZT-DQ01 and ZT-DQ02 (March 2025) - Page 1
Forum section: electronics / testgear

author: tunk
author_rank: Super Contributor
timestamp: March 18, 2025, 11:07:32 pm
content: Not much known, a couple of short youtube videos and listingson taobao for 398cny (approx. US$55). Looks like they go up to100kHz. Maybe someone fluent in Chinese can translate?https://youtu.be/4P8oAf-e9S0https://youtu.be/J6vSK0-G3DQhttps://world.taobao.com/item/896215678576.htmhttps://world.taobao.com/item/897044680851.htm

author: Atlan
author_rank: Frequent Contributor
timestamp: March 19, 2025, 04:31:08 am
content: Give it time, it came out a week ago.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 28, 2025, 08:13:05 pm
content: i ordered the bigger 02 model with many clips on Aliexpress total at 81$ usd with accelerated shipment ....on ALI the same model can start at 67$ usd, same options if you do some search, before not after .... lollBangood has them, at 4 $ usd more ....my only question, for the kelvin clips, seems to have an plug, round or square ? or where it goes ? must be on top, like their dmm scopes ?

author: Atlan
author_rank: Frequent Contributor
timestamp: March 29, 2025, 08:32:31 am
content: Link on aliexpres with full equipment

author: RAPo
author_rank: Super Contributor
timestamp: March 29, 2025, 09:01:23 am
content: I bought the ZT-DQ02.

author: Aldo22
author_rank: Super Contributor
timestamp: March 29, 2025, 09:12:49 am
content: Quote from: Atlan on March 29, 2025, 08:32:31 amSnakol Global:https://www.aliexpress.com/item/1005008703519215.html

author: coromonadalix
author_rank: Super Contributor
timestamp: March 29, 2025, 11:03:32 am
content: yep same seller ZT-DQ02 with clip

author: tunk
author_rank: Super Contributor
timestamp: March 29, 2025, 02:31:10 pm
content: Looks like the difference is that the ZT-DQ02 can measureinternal battery resistance (0.1mΩ-200Ω). Other specs below.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 29, 2025, 02:36:18 pm
content: and one big difference if its true its the display count never saw that many countmany 20k or 40k on the market ...curious to see an teardown of it, if they are based on 2 ic ones like the de5000 or else .... at that price, the part count must be low ??

author: DaneLaw
author_rank: Frequent Contributor
timestamp: March 29, 2025, 09:22:52 pm
content: Are DQ02 variants using a secondary socket for the battery-resistance feature?Its displayed acc-portfolio seems to include the common aviation-like screw-in terminal that you find on most of the battery resistance meters.

author: RAPo
author_rank: Super Contributor
timestamp: March 29, 2025, 11:08:52 pm
content: Yes. Connection is on the top of the meter.

author: Cyclotron
author_rank: Unknown
timestamp: March 30, 2025, 01:52:10 am
content: Another day, another bit of test equipment purchased. I'm curious to check this out at this price.

author: LeonR
author_rank: Regular Contributor
timestamp: April 07, 2025, 03:48:29 pm
content: So, anyone received their already? How does it fare compared to more known brands?

author: RAPo
author_rank: Super Contributor
timestamp: April 07, 2025, 03:52:30 pm
content: mine is on the slowboat/plane from china, out for delivery on 19th April.Will test it against hantek/uni-t and Der-EE

author: coromonadalix
author_rank: Super Contributor
timestamp: April 07, 2025, 06:24:08 pm
content: teaser ..... mine is on my door step, i asked a neighbor to take it and keep it safeill check it when home

author: DaneLaw
author_rank: Frequent Contributor
timestamp: April 07, 2025, 08:02:26 pm
content: Quote from: RAPo on March 29, 2025, 11:08:52 pmI see... (thx)Could look like an XS10 aviation quick connector?Which is quite common on Chinese budget battery resistance tester/meters.. It tends to be either the 4pin-XS10 or the 4pin-GX12.XS10 is preferred IMO for the "quick" click & pull aspect, but if the pinout matches and it is an XS10 interface, it would likely work with any of these Kelvin probes and battery LIion rigs for fx Yaorea (1035).

author: coromonadalix
author_rank: Super Contributor
timestamp: April 07, 2025, 09:02:31 pm
content: ok so farBased on Artery MCU but sanded off pretty good on the part numberon FW upload it list as : AT32 Msc iap Device in hard drives section in the windows hardware manageron powered and usb connected, list as an com port device 9600 by defaultcan be used while powered by usb-c cable if the battery is removed, red power button while charging, green when charged.The case is hard to open, the middle section hold pretty strongly by snaps, used an X-acto blade to slightly force itThe round kelvin plug cables are fragile, was not properly screwed, and stress relief too, this one may fail fastThe case seems solid and sturdy, and does not deform if i try to pry on itsolders on the top connector pcb are so so, could have been done better, i did re-solder themsame on the input pcb who connect to the main pcb thru 0.1" pins headersfor sure flux residues on soldersfunny the lcd screen slide to the side once the flex is unplugged, they say on the specs 320x240 at 2.8" sizeas per manual, with precision resistors (non inductive) you seems to be able to re-calibrate it ?? need to read more ...Tried battery resistance tests: seems okay, tried on rechargeable ... but you need the kelvin on the top of the lcr, it will beep after a few sec to tell it is okay, or measurement is done ?and for sure RTFM lollArtery Website Tools etc ....https://www.arterychip.com/en/support/

author: Dominik
author_rank: Newbie
timestamp: April 08, 2025, 04:25:16 am
content: Thank you coromonadalix for the first review.Do you think it could compete with the de5000? Did you own a de5000, so you could compare meassured values?

author: coromonadalix
author_rank: Super Contributor
timestamp: April 08, 2025, 10:14:36 am
content: the de5000 has an open and short calibration, it was an 2 ic solution lcr meterthis one seem slightly more elaborated (more parts) input protection seems good ? heavier in weight and seems more rigid for sure, and has colors lollfor this one Zoyi mmm i'm reading manual ... but it enter more a full calibration and battery calibration, haven't seen an open short leads calibration ...as of fw v 1.0.5 only english and chineese for language selectioncan't do a compare between them, i don't have any precision capacitors or elseI bought it for the kicks of it, and low pricing and long term testing ...On Ali Express the Hantek 1832 1833 prices seems to have dropped, and the de5000 too, Newest Uni-T models are expensive, the old 612 seems okay (same tech as DE5000)The ET43x models .. some have dropped in pricesChecked Zoyi main web site and the 2 lcr's models haven't been put on display ? yet ?oh and the input bar we see on the photo, is not a metal short bar, it's an blank fr4 board ?

author: bffargo
author_rank: Regular Contributor
timestamp: April 08, 2025, 03:39:49 pm
content: Thanks. Didn't stumble on it over the weekend when there were the extra sale and couponsI placed order last night for the deluxe DQ02 model from SNAKOL store for $71 USD shipped after coins and coupon discounts.Possibly my last overseas order to make it in before the massive U.S. tariffs and removal ofde minimistakes place May 2. The AliExpress / direct-from-CN train is at the end of the line here in the states

author: mawyatt
author_rank: Super Contributor
timestamp: April 08, 2025, 04:31:33 pm
content: Quote from: coromonadalix on April 08, 2025, 10:14:36 amIf you don't have any precision caps, use some film and/or NPO/COG ceramic types and measure and compare with your DE-5000. Also you could use some precision resistors to see how theRof the LCRperforms.How does this manual recommend doing the "Open" and "Short" Calibrations with just a blank FR4 board? Seems (maybe) this would work for the "Open" but not for the "Short" for cases where no external leads are utilized. Normally the Hcur and Hpot are shorted and separately the Lcur and Lpot shorted for the "Open" Calibration, then the H and L pairs are shorted together for the "Short" Calibration.This looks like a well designed and produced handheld LCR Meter, curious how it performs.Best

author: coromonadalix
author_rank: Super Contributor
timestamp: April 08, 2025, 05:20:57 pm
content: Manual say calibration mode, but with many parts / values and voltages ... not the basic check, like open close/short tests before use, like i do on the de5000i'm not saying it's bad, but it was something i tried to find, still checking the lcr menus and where / what it does when selectedAs the other mentioned models, same thingsi don't know if they have similar checks upon power up or idling for a few minutesi do question that weird fr4 short bar look a like ? open the contacts for sure, but ?I love the pouch and all the test leads who comes with it (Full Kit) not too flexible and not too hard, quality seems good, the lcr banana insertion force is good

author: mawyatt
author_rank: Super Contributor
timestamp: April 08, 2025, 06:37:13 pm
content: BTW on your DE-5000 try using a "Direct" Open Short Cal without the TL-21 Fixture. We made a Shorting Bar from a thin Copper sheet cut and filed/sanded as shown. We get very good agreement with High and Low Z leaded components with our Lab LCR Meters (TH2830 & IM3536) using this direct method without the TL-21.We get about 0.6pF, 0.16uH, and 0.33Ω at 100KHz , and 0.3Ω DCR when doing an Open Cal then installing the Shorting Bar for Short Cal, then installing the TL-21 and making Open and Short LCR measurements. This shows how much complex Z is added to the measurements with the TL-21, even tho this is effectively "removed" with a good Open/Short Cal with TL-21 in place. The TL-21 is quite good IMO and does an excellent job with the short length alligator clips with terminated 4 Wire Kelvin connections, but the Direct method is a little better for many leaded components.Would be interesting to "see" how the new Zoyi behaves and if the "Direct" leaded measurements and Open/Short Cal is possible.Anyway, here's an image of the Shorting Bar we made.Best

author: tszaboo
author_rank: Super Contributor
timestamp: April 08, 2025, 07:48:53 pm
content: This is a reminder for the user tszaboo that you already have a Uni-T 612, that you bought recently (used), for a good price, you barely use it, and you don't need another cheap LRC meter.

author: Atlan
author_rank: Frequent Contributor
timestamp: April 09, 2025, 11:04:12 am
content: It's already home, it looks functional. I don't like the rubber buttons with the description a bit, it looks like the white description will disappear over time.

author: Serg65536
author_rank: Regular Contributor
timestamp: April 09, 2025, 09:54:08 pm
content: Quote from: coromonadalix on April 08, 2025, 10:14:36 amPlease post pictures of the instruction manual. It's not available yet.

author: Atlan
author_rank: Frequent Contributor
timestamp: April 10, 2025, 04:46:28 am
content: 1

author: Atlan
author_rank: Frequent Contributor
timestamp: April 10, 2025, 04:47:55 am
content: 2

author: Atlan
author_rank: Frequent Contributor
timestamp: April 10, 2025, 04:51:00 am
content: 3

author: indman
author_rank: Super Contributor
timestamp: April 10, 2025, 06:29:27 am
content: I think I should wait until they make the ZT-DQ03 with a 3.5 inch display. Similar to ZT-703S

author: Atlan
author_rank: Frequent Contributor
timestamp: April 10, 2025, 07:27:04 am
content: I don't see a reason. Yes, the cover is pre-printed for a larger display, but everything is large enough on the given display size.P. S. The case for the device is not the best. It probably wasn't designed for all the cables. I would have liked a larger case with a separate section for the cables, which would have limited the amount of cables scratching the display like they do now.

author: indman
author_rank: Super Contributor
timestamp: April 10, 2025, 07:34:33 am
content: Quote from: Atlan on April 10, 2025, 07:27:04 amYou didn't convince me. For a person with poor vision, 3.5 inches is better than 2.8. Plus, the larger display can hold more useful information.I'm waiting ZT-DQ03.

author: coromonadalix
author_rank: Super Contributor
timestamp: April 10, 2025, 08:38:50 am
content: if there is one who'll come out lollsure 2.8" can be small, wont argue on that ...for the price, i'm satisfied with it

author: RAPo
author_rank: Super Contributor
timestamp: April 10, 2025, 12:44:31 pm
content: My device still hasn't arrived, but if I compare it to the Hantek and uni-T 612, it seems to have the same readability.Quote from: indman on April 10, 2025, 07:34:33 am

author: mawyatt
author_rank: Super Contributor
timestamp: April 10, 2025, 03:41:12 pm
content: The "insulating spacer" now makes sense as shown in the manual images. Inserting it causes the 'blades' in the slots of the Hcur and Hpot which are normally shorted together as are Lcur and Lpot 'blades' to separate and "Open". Without this effectively makes the external Kelvin connections ineffective as the Kelvin connections are completed inside the meter slots. Inserting the insulator spacer separates the H and L blades allows proper external Kelvin Sensing.Also noted in the manual images, that a Calibration can be performed with a Short (0 Ω) and Open separately and/or alone without the need for the other resistance calibration values. This is like most other LCR Meters we have experience with, and the ability to use various precision resistors as Calibration Standards in a nice additional feature IMO.From what we've seen in the manual images, one could construct a 'Shorting Bar' like we've done for our DE-5000 and do a Short Calibration, then an Open Calibration which should produce the most repeatable results for high and low Z leaded components.Wonder if Zoyi will offer a Shorting Bar like Tonghui has for their Bench LCR Meters?This looks very interesting and curious how the ZT-DQ01 compares with the DE-5000 or other known LCR meters wrt accuracy and repeatability. If we had one would be more than happy to compare with our TH2830 and IM3536 Lab Bench LCR MetersAnyway, thanks Atlan for posting the manual imagesBest

author: bffargo
author_rank: Regular Contributor
timestamp: April 10, 2025, 06:16:23 pm
content: Will this clip work with it? I see some have thin legs and others have thick will both work or only 1?https://www.aliexpress.us/item/3256805897134521.html

author: coromonadalix
author_rank: Super Contributor
timestamp: April 10, 2025, 06:40:19 pm
content: seems to be compatible the guard and others does fit the Zoyiand they seems to be less expensive as many on the same site or Ebay etc ...

author: Atlan
author_rank: Frequent Contributor
timestamp: April 10, 2025, 06:43:57 pm
content: What's better than the 4 cables that come with the device?

author: bffargo
author_rank: Regular Contributor
timestamp: April 10, 2025, 07:22:14 pm
content: Quote from: coromonadalix on April 10, 2025, 06:40:19 pmEven better with the last of my Coins to use up tooSadly their own images have both the thin tabs and wider ones, and user images don't show them. One said it didn't work well with the Hantek?

author: bffargo
author_rank: Regular Contributor
timestamp: April 10, 2025, 07:26:18 pm
content: Quote from: Atlan on April 10, 2025, 06:43:57 pmIs that a statement or question? Is the clip + slot considered better connection than the 4mm banana plugs? Also not sure the gauge of the wire on the included ones with the 02?

author: coromonadalix
author_rank: Super Contributor
timestamp: April 10, 2025, 07:35:17 pm
content: Quote from: bffargo on April 10, 2025, 07:22:14 pmBought the same well see

author: mawyatt
author_rank: Super Contributor
timestamp: April 10, 2025, 07:45:50 pm
content: Quote from: bffargo on April 10, 2025, 07:26:18 pmWe had assumed that image shows a shorting bar, but apparently it's a "Spacer Bar" which is required when using the Banana Sockets to keep the blades in the slot "open" so the Kelvin connection is thru the Banana Sockets and not directly in the slot.With that ^ in mind it would seem the Kelvin Clips with the Blade Fixture might be better (if it fits properly) as it eliminates the need for the "Spacer Bar".Would think that Zoyi would include this Fixture (if it fits properly) rather than the Banana Jack based Kelvin Clips and Spacer Bar. Maybe they will in the future??Best

author: Serg65536
author_rank: Regular Contributor
timestamp: April 11, 2025, 10:51:23 am
content: Sothere are open and short calibration modes!Actually, there are two separate menu entries for calibration, which include open and short calibration.Can anybody confirm that two calibration modes exist, so this is NOT the instruction manual glitch?Unclear is:1. When to use and what type of calibration?2 How large isshort circuit drift? (should be temperature dependent)3 How large isopen circuit drift? (should be temperature and humidity(?) dependent)4 Does the device calibrate adjacent ranges to compensate open and short drift? (probably not, because there are separate calibration entries for each range)Knowing the answers to these questions would dramatically increase the actual accuracy of the device.

author: LeonR
author_rank: Regular Contributor
timestamp: April 11, 2025, 02:41:39 pm
content: Quote from: bffargo on April 10, 2025, 07:22:14 pmZiboo have a youtube channel. Maybe they're willing to share their test results?https://www.youtube.com/@ZIBOO-Official/videos

author: RAPo
author_rank: Super Contributor
timestamp: April 12, 2025, 03:18:17 pm
content: Yes, that Kelvin clip will work (I just tested my DQ02 with exactly this clip).Quote from: bffargo on April 10, 2025, 06:16:23 pm

author: RAPo
author_rank: Super Contributor
timestamp: April 12, 2025, 03:23:39 pm
content: There are two calibration modes:Method 1 for the LCRMethod 2 for the Battery tester.Method 1 has open/short and several resistance calibration settings: press the value you want to calibrate, press auto, and the bar will turn yellow, and after 30-45 seconds, screen will turn green if the calibration is okay.Method 2 can also be used to calibrate voltage settings.Quote from: Serg65536 on April 11, 2025, 10:51:23 am

author: RAPo
author_rank: Super Contributor
timestamp: April 12, 2025, 03:26:33 pm
content: The manual states that you can log values using SCPI. The manual doesn't elaborate. Has anyone more info?

author: RAPo
author_rank: Super Contributor
timestamp: April 12, 2025, 03:29:25 pm
content: I did a short test of the battery tester, both before and after calibration, and the Fnirsi HRM-10 is more accurate.Still, a nice function to have.

author: Atlan
author_rank: Frequent Contributor
timestamp: April 13, 2025, 04:51:22 pm
content: Maybe firmware 107 ?https://www-mydigit-cn.translate.goog/thread-515071-1-1.html?_x_tr_sl=auto&_x_tr_tl=sk&_x_tr_hl=sk

author: bffargo
author_rank: Regular Contributor
timestamp: April 13, 2025, 05:14:36 pm
content: Quote from: Atlan on April 13, 2025, 04:51:22 pmDo you have invitation codes for that forum? Seems you can only sign up from invite from existing members.

author: tunk
author_rank: Super Contributor
timestamp: April 13, 2025, 05:27:35 pm
content: Could look like v106 for ZT-DQ02 is here:http://www.szzotek.com/h-col-159.html

author: RAPo
author_rank: Super Contributor
timestamp: April 13, 2025, 05:51:11 pm
content: I'm on V1.05Quote from: Atlan on April 13, 2025, 04:51:22 pm

author: Atlan
author_rank: Frequent Contributor
timestamp: April 13, 2025, 06:08:24 pm
content: Quote from: bffargo on April 13, 2025, 05:14:36 pmI don't have one, but that wasn't the purpose of the post. Just information that something is probably being worked on. Also, let the local guys try it out before it gets to usi have fw105From a Chinese forumThis bridge does not have a DCR 0Hz setting. Customer service said it might be updated later.I'm curious.

author: RAPo
author_rank: Super Contributor
timestamp: April 14, 2025, 02:39:59 pm
content: I've upgraded to V1.06. Don't see much difference.Quote from: RAPo on April 13, 2025, 05:51:11 pm

author: Atlan
author_rank: Frequent Contributor
timestamp: April 14, 2025, 04:15:56 pm
content: There are a lot of bugs to fix. We'll see if most of them can be fixed by the time V110 is released, Chinese people say.

author: Serg65536
author_rank: Regular Contributor
timestamp: April 14, 2025, 08:39:02 pm
content: My Zoyi DQ01. Big part of the board is not populated. There is no match for $42...

author: Serg65536
author_rank: Regular Contributor
timestamp: April 14, 2025, 08:56:44 pm
content: INA826 differential instrumentation low power op amp. Is it good for 100kHz? Probably just barely enough...What is 49 p113 ti chip?tc4056 for charger.

author: Serg65536
author_rank: Regular Contributor
timestamp: April 14, 2025, 09:08:29 pm
content: MS8606 is low voltage dual general op amp 10MHz BW.

author: coromonadalix
author_rank: Super Contributor
timestamp: April 15, 2025, 12:05:30 am
content: updated to 1.0.6 can't see any differences ? nice idea to just drop a file in it when in usb bootit create a drive in windows explorer, drop it in, and voila ...

author: andre3d
author_rank: Contributor
timestamp: April 15, 2025, 12:10:04 am
content: p113 is PGA113AID -Zero-Drift Programmable Gain Amplifier With MuxSimilar scheme LCR Tweezers Bridge Tester see attachment

author: coromonadalix
author_rank: Super Contributor
timestamp: April 15, 2025, 02:02:48 am
content: have you seen this one lollhttps://www.banggood.com/LCR-P1-Pro-Smart-LCR-SMD-ESR-Tester-Precise-Measurements-Capacitance-Inductance-Resistance-1200mAh-Battery-1_54-inch-Color-Screen-Portable-Testing-Tool-for-Continuity-p-2021059.html?

author: Daniil.Lab
author_rank: Contributor
timestamp: April 15, 2025, 09:12:21 am
content: I also bought the ZT-DQ02 model with all the cables on Ali. It will arrive on April 25, let's see what kind of beast it is. At work I have a Hantek 1833C and an FNIRSI HRM-10, I'll compare how the ZT-DQ02 batteries measure, I also have an ET433, I'll see who's more flashy )) oh, the latter are expensive for me...The ZT-DQ02 cost me $78.96

author: mawyatt
author_rank: Super Contributor
timestamp: April 16, 2025, 05:15:20 pm
content: Quote from: RAPo on April 12, 2025, 03:29:25 pmHow much of a difference did you experience?Have you or anyone done an actual comparison of known R and C components with another reference LCR meter(s)?BTW does the Battery Test Function have better resolution in the R measurement than the LCR Function? Seems this is 0.1mΩ vs 1mΩ from the manual images.Best

author: RAPo
author_rank: Super Contributor
timestamp: April 16, 2025, 05:28:47 pm
content: I´m planning to make a test report this weekend, using DMM check plus, the DQ02 and uni-T and hantek lcr meters.Quote from: mawyatt on April 16, 2025, 05:15:20 pm

author: ass20
author_rank: Regular Contributor
timestamp: April 16, 2025, 07:25:55 pm
content: i Found review from chinahttp://www.dt830.com/thread-94-1-1.htmlI recive ZT-DQ2 and make little test/ Firmware 1.05REC and REL mode do not work i press and hold this buttons but i do not see changesbutton REL% work only with active resistor... with capacitors do not workBattery celvin clips do not compatiable with gx connectors, used in YR1030 YR1035 RC3563in user manual written about SCPI commands... but do not info about SCPI command list or softwareFor calibraion need many precission resistors

author: DaneLaw
author_rank: Frequent Contributor
timestamp: April 16, 2025, 07:51:40 pm
content: Quote from: ass20 on April 16, 2025, 07:25:55 pmThey are not using the same connector.As I speculated earlier in this thread. [#15] on the standard used in YR1035.While YR1030 is using USB-A, while RC3563 (if I recall correctly) are using GX16-4pSo, what model of Kelvin clips did you try with?Obviously not YR1030, as that one is based on a USB-A-socket (same as DC-YR2050, as I'm cycling Kelvin-clips between those two models)While the one I speculated could be used was YR1035, and perhaps without any modifications if the pinout matches.YR1035 =RC3563 =YR1030 =

author: RAPo
author_rank: Super Contributor
timestamp: April 16, 2025, 08:07:33 pm
content: I've emailed Zoyi about the scpi interface. Snarkol was very responsive but did not know the answer. Hopefully Zoyi will respond. I used the supplied probes of each device. Indeed connectors cannot be interchanged.If you long press the rec mode a com-port will popup in win-11, but also an unknown decide driver message. It would be great if it was an Hid device just like the GW Instek LCR-1100.Quote from: ass20 on April 16, 2025, 07:25:55 pm

author: coromonadalix
author_rank: Super Contributor
timestamp: April 16, 2025, 10:29:28 pm
content: annnd the prices has began to slowly rise from the same seller and others .... but they give an 10$ off loll@Rapo, as soon it is powered and USB-C connected, you have a com port appearing ?? no drivers neededin flash mode it's an other kind of device who appearsAND for me, better focus on FW stability and functions than implementing scpi commands unless you do binning logging binning production related stuff ...

author: RAPo
author_rank: Super Contributor
timestamp: April 17, 2025, 06:39:44 am
content: When I long-press on HOLD/REC, the com-port appears as described in the manual on page 12.The com-port is a usual USB-serial device. No drivers needed.Quote from: coromonadalix on April 16, 2025, 10:29:28 pm

author: coromonadalix
author_rank: Super Contributor
timestamp: April 17, 2025, 01:24:23 pm
content: but you don't need to hold anything when you connecton mine DQ02 v1.05 or now v1.06 as soon it is powered up, it connect into windows automatically if your Usb-C cable has data wires in itx/d/q /0 ESR is for the FW upgrade ??Sorry i'm not following ... what do you intend to do when usb connected, if it is not charging ?? poke in the lcr firmware ?

author: ass20
author_rank: Regular Contributor
timestamp: April 17, 2025, 01:42:44 pm
content: board have swd connector itis pin outuart tx PA9/SWCLK/GND/SWDIO/3.3Vfor connect to cpu need remove battery and use 3.3v from jlink , daplinkNeed connextor with 2.0mm step (NOT 2.54)CPU is lockedArteryICPProgrammer said the cpu is at32f403Z (tqfp144) but real cpu is tqfp100 package... used custom cpu ?On reference manual for at32f403 written DEBUG device ID (DEBUG_IDCODE) is 0xE0042000The DEBUG_IDCODE register ismapped on the external PPB bus at address 0xE0042000. This code is accessible by the JTAG debugport or SW debug port or by the user codeBut i cannot read this adress

author: RAPo
author_rank: Super Contributor
timestamp: April 17, 2025, 01:51:17 pm
content: Read page 12 from the manual: You can automate measurement by sending SCPI codes.So you can write a program that iterates over eg the levels and frequency, and save the results to a file.but to get that working you need to get in the USB-Com port (or maybe USb-HID device).Like Rudi does on his newly bought GW-instek:Quote from: coromonadalix on April 17, 2025, 01:24:23 pm

author: RAPo
author_rank: Super Contributor
timestamp: April 17, 2025, 01:52:52 pm
content: Thanks usefull info!Quote from: ass20 on April 17, 2025, 01:42:44 pm

author: coromonadalix
author_rank: Super Contributor
timestamp: April 18, 2025, 10:30:49 am
content: from Artery you have many softwares, bootloaders isp etc ...and maybe unpack the firmware like they try on the Zoyi handheld 703 scope ??sure scpi would be nice to have ... but this lcr is not for production purposes ? and they claim 100mF / 100,000uf loll alas no capacitor to test that affirmation loll

author: ass20
author_rank: Regular Contributor
timestamp: April 18, 2025, 01:36:41 pm
content: I do not know why main chip (tqfp100) mark is clean but other chips is not clean...May be is not artery chip ? or artery chip clone ? I connect to chip whith artery tool... and it said at32f403Z chip (Z is qfp144) ...scpi command may be found in FW update file v1.06Any body have fw update file with vwrsion 1.05 . please uploadwhat softawe may be use for test scpi commands ? without labView etc..

author: andre3d
author_rank: Contributor
timestamp: April 18, 2025, 06:24:40 pm
content: It may be there AT32F403AVGT7 LQFP100 (in ZT-702S).

author: coromonadalix
author_rank: Super Contributor
timestamp: April 19, 2025, 01:33:58 am
content: seems to fit #55 posted picturemost of the supply and ground lines, and the osc pinscould be our suspect thksas for scpi tests, you can install rhode schwartz visa, they have tester 32 and tester 64 tools to communicate / send command

author: gehka3
author_rank: Newbie
timestamp: April 22, 2025, 03:38:51 pm
content: And this device arrived to me, in full maximum configurationOn the pleasant side - firmware version 106 was already in the deviceI checked it on in-circuit measurements, manually setting the element type, voltage level, frequency, measurement speedI used adapted bridge tweezersWhat can I say - the application is limited for such a purpose, at least in my configurations, but overall a satisfactory ratingCapacitors (SMD ceramics) in PWM strapping - shows quite adequately, in the feedback of power circuits - here are the problems, changing the settings has little effectResistors - depending on the circuit and the presence of other elementsMaybe they will improve a little with the release of new firmware?

author: coromonadalix
author_rank: Super Contributor
timestamp: April 22, 2025, 07:32:08 pm
content: received post #35 leads from ali express works very well, finger / pcb thickness are ok@gheka serial parallel mode do help, but they are not absolute, it really depend of what you have in your circuitbecause on my de5000 i did ended up with some kinda self oscillating circuit, i simply removed the part and tested outside,the biais voltage is limited, not to damage parts but sometimes it is not enoughwell see over time ? ... i do hope the company is hearing our thoughts and comments

author: gehka3
author_rank: Newbie
timestamp: April 23, 2025, 03:58:34 am
content: Similarly, on this device I sometimes observe self-excitation, with tweezers and on the original complete cordsSomeday I will analyze the circuit and perhaps it will be possible to improve the stability

author: indman
author_rank: Super Contributor
timestamp: April 23, 2025, 05:21:18 am
content: Many people have already received this device, but I have not yet seen any competent review or comparison of readings with other well-known LCR meters?Can I trust the readings of this product or as I wrote above I should wait until ZT-DQ03(4) is released?

author: coromonadalix
author_rank: Super Contributor
timestamp: April 23, 2025, 10:27:00 am
content: you can wait or buy products who are on the market way longer than this one, sure i did bought it knowing thatde-5000 is a basic 2 chip lcr, many others on the same design, and you have many others on the market ... choice is your's, some are proven okay and don't have known bugs, but priceyi did try 10mF caps yesterday too, the last lcr digit do wobble a tiny bit, but i get expected values, tested with 0.035% precision resistors and others, and other type of caps (non precision) so far, it fit the bill, i did not test in circuit serial or parallel mode, i'm more the type who remove parts to do better teststhe fw has or may contains errors or else, over time it may get better if Zoyi do updates and hear all users comments, they seems to some extenti dont have better lcr, bench types etc ... i can not do better compare, others may do ...you'll have to wait or be a guinea pig testing it and see ? keep in mind that's a new product.

author: indman
author_rank: Super Contributor
timestamp: April 23, 2025, 11:51:49 am
content: coromonadalixThank you, I already have a ZOYI ZT-703S as a guinea pig.I just like the ZT-703S form factor and its large, clear display.If I were sure that the ZT-DQ02 copes with the task of measuring LCR no worse than the DE-5000, I would buy it now. But I'm not sure about that at all.By the term copes no worse, I mean not only reliable measurements of the main parameters of the LCR, but also secondary parameters, which are sometimes no less important than the main ones.Therefore, we will wait for a full review of this model.

author: gehka3
author_rank: Newbie
timestamp: April 23, 2025, 12:31:07 pm
content: Maybe this information will be usefulI looked at the signal with an oscilloscope in the capacitor measurement mode, on the bridge tweezers, at different voltage levels and frequencies100 kHz 0.1v, 0.3v and 0.6v respectively, a running surge is observed at voltage values ​​of 0.1v and 0.3v, at a voltage of 0.6v the sine is pureThe same behavior at other frequenciesNot critical for measurementsI checked it on a product with a short circuit on an element in the power supply circuit - you can localize the section according to readings in thousandths of an Ohm

author: bffargo
author_rank: Regular Contributor
timestamp: April 24, 2025, 02:25:04 am
content: Quote from: daisizhou on April 23, 2025, 10:42:54 pmWasn't one of the tear down videos (on the ZT-70xS series) saying that they used a protected cell instead of plain cell and that added extra length to the cell causing it to cram the spring tightly.

author: Serg65536
author_rank: Regular Contributor
timestamp: April 26, 2025, 09:30:43 am
content: DQ01 is a 80 000 counts device.It's on device renders, but not mentioned in the manual.Ranges with full 5 decimal digits available (up to 80 000 counts):1.0000-8.0000 Ohm (below 1 Ohm it's limited to 0.1 mOhm resolution)10.000-80.000 Ohm100.00-800.00 Ohm1.0000-8.0000 kOhm10000-80000 kOhm100.00-800.00 kOhmEg.: above 8 at the first position we loose 1 digit of resolution. So 7.9999 Ohm jumps to 8.001 Ohm.0.800-0.999 MOhms 3 digits!!! (uppercase "M" stands for mega Ohms, not milli Ohms)This is some FW glitch! It should NOT be this way!1.000-7.999 MOhm 4 digits8.00-9.99 MOhms 3 digits!!!above 10.00 MOhm 4 digits again. WHY!!!?? the accuracy is horrible, much worse than below 1 MOhm...I have DQ01 fw 105.

author: FixyMixy
author_rank: Contributor
timestamp: April 26, 2025, 01:26:10 pm
content: Quote from: Serg65536 on April 26, 2025, 09:30:43 amThis is a horrible resolution! From almost 5 digit device it degrades to 3 digits in the middle of measurement range!I hope zoyi fix this!

author: Serg65536
author_rank: Regular Contributor
timestamp: April 26, 2025, 04:03:38 pm
content: Quote from: gehka3 on April 22, 2025, 03:38:51 pmCan anybody with fw v106 confirm 3 digit resolution from 800 kOhm to 1 MOhm and from 8 MOhm to 10?

author: FixyMixy
author_rank: Contributor
timestamp: April 26, 2025, 04:05:51 pm
content: Quote from: ass20 on April 18, 2025, 01:36:41 pmPlease, share the 106 firmware, I can't find it anywhere!

author: Atlan
author_rank: Frequent Contributor
timestamp: April 26, 2025, 04:36:50 pm
content: https://www.eevblog.com/forum/testgear/new-lcr-meters-zoyi-zt-dq01-and-zoyi-zt-dq02-(march-2025)/50/

author: coromonadalix
author_rank: Super Contributor
timestamp: April 26, 2025, 05:00:07 pm
content: Quote from: FixyMixy on April 26, 2025, 04:05:51 pmattachedfor the DQ02 but it would be nice to know if it fits on a DQ01 ?? surely there must be some mcu id / model id somewhereIn the FW upgrade the lcr appears as a storage drive, you drop the fw in it ...

author: Serg65536
author_rank: Regular Contributor
timestamp: April 27, 2025, 08:34:52 am
content: Quote from: coromonadalix on April 26, 2025, 05:00:07 pmIt's NOT RECOMMENDED to upgrade DQ01 with the DQ02 firmware, because it does not check hardware before flashing the firmware.I've just upgraded my DQ01 with the DQ02 firmware. It fixed the TOL% function, but added battery test mode to the "LCRZ" button. There is no battery calibration menu entry in the settings. I guess there should be calibration data in the flash to access the missing menu.So now I'm at risk of having my device malfunction with future upgrades or existing software issues linked to the absence of battery testing circuitry.

author: indman
author_rank: Super Contributor
timestamp: April 27, 2025, 08:57:40 am
content: Quote from: Serg65536 on April 27, 2025, 08:34:52 amSo what prevents you from returning the firmware for DQ01, since it is also available via the link that was given to you earlierAtlan?

author: Atlan
author_rank: Frequent Contributor
timestamp: April 27, 2025, 10:22:11 am
content: Write to zotek, let him send you the firmware for dq1

author: coromonadalix
author_rank: Super Contributor
timestamp: April 27, 2025, 10:58:46 am
content: this is supposed to be for the dq01version 1.0.5 i downgraded my DQ02 to a DQ01 and reversed it back ... works ok calibration i dont know seem fine.I think @Serg65536 you can put back this oneAnd people seems nervous about theses lcrsthey are new and buggy, pls wait to buy them or live with their bug's until Zoyi iron them outi asked for FW, silence for now ...

author: Serg65536
author_rank: Regular Contributor
timestamp: April 27, 2025, 11:32:41 am
content: New video from zoyihttps://youtu.be/4kmUZNEwCLI

author: indman
author_rank: Super Contributor
timestamp: April 27, 2025, 11:46:34 am
content: Quote from: Serg65536 on April 27, 2025, 11:32:41 amThanks, but this is a sad video. Despite the resolution of 80,000, I don't see any stability in the results on the display, even close.So it looks like a random number generator in the last digits.So far, this device is not worth the money that is being asked for it. Just don't convince me that you don't have to wait for a quality product for $50-60. Everyone has their own ideas about value.We are waiting for the DQ03-4 version.

author: andre3d
author_rank: Contributor
timestamp: April 27, 2025, 12:26:04 pm
content: Zotek ZOYI ZT-DQ02 review

author: Serg65536
author_rank: Regular Contributor
timestamp: April 27, 2025, 12:33:58 pm
content: Quote from: indman on April 27, 2025, 11:46:34 amIt's stable on almost all ranges.One last count bounces +-1 sometimes.I can't agree with a point that it is not stable!Few tips for stability:- disconnect leads and use the build in socket;- use shielded leads;- make sure all 4 terminals are connected to the part, but NOT to each other.- don't touch the part under measurement;- use slow measurement speed setting, wait a couple of measurements to complete;- read the tolerance table from the manual, don't use the device outside specified range. Though it show some values, but they are bouncy and unreliable.It's not industrial grade device, use it in low EMI environment.

author: coromonadalix
author_rank: Super Contributor
timestamp: April 27, 2025, 11:06:57 pm
content: the best handheld would be the old BK 885 886 or Motech variants .... they had an dds (frequency synthesizer) ic in them ....but as written i think the mcu does a lot, as many designs, many lcr's are 20k counts some 40k counts etc ... this one goes the furthestas stability concerned ... i see only the last digit flicking once in a while, if i use the low speed measurements, it is more stable, i use the newly bought kelvin fixture posted here, not the included ones (banana plugs)not i myself would say it's a good designeven with an Sencore LC102 or the De5000 just being near it, can affect it, clips quality and other factors ...IE: the Sencore is very peculiar for its test cable, RG62b nothing else, if not, the open or short test will absolutely failsome bench meters have tests fixtures for lots of $ just to be sure it's good when you go less than 1% precision ...as for the video i think you need to put the blank fr4 pcb in the kelvin slots, to be sure it wont interfere with the banana plugs

author: andre3d
author_rank: Contributor
timestamp: April 28, 2025, 07:36:53 am
content: ZOYI DQ02 bug ?https://www.bilibili.com/video/BV1JfLczdEnu/?spm_id_from=333.337.search-card.all.click

author: indman
author_rank: Super Contributor
timestamp: April 28, 2025, 07:49:56 am
content: Quote from: andre3d on April 28, 2025, 07:36:53 amThis is an even more sad video than the one that we were shown before. Especially when the secondary parametersDare compared in various containers.

author: Propretor
author_rank: Regular Contributor
timestamp: April 30, 2025, 06:23:05 am
content: That's weird. Very contradictory opinions about the device. It is confusing that there is no mention and support on the official website.

author: coromonadalix
author_rank: Super Contributor
timestamp: April 30, 2025, 10:22:48 am
content: yeah same hereif people do ask Zoyi, or tell them problems on the lcr's maybe tey'll be more inclined to do fw updates faster ? i did ask ...

author: Propretor
author_rank: Regular Contributor
timestamp: April 30, 2025, 10:49:21 am
content: Quote from: coromonadalix on April 30, 2025, 10:22:48 amI emailed them too, but never got a response. No answer about the site or firmware.

author: Propretor
author_rank: Regular Contributor
timestamp: April 30, 2025, 10:53:48 am
content: Quote from: daisizhou on April 30, 2025, 10:48:58 amWhat do you mean? I own the NV-19 measuring tweezers and they are very good!!!https://www.rlc-esr.ru/index.php/ru/pintset-nv19The developer of the tweezers is not a very friendly and outgoing person, but his tweezers are excellent! I don't mean beauty, but functionality and features.

author: indman
author_rank: Super Contributor
timestamp: April 30, 2025, 11:17:26 am
content: Quote from: Propretor on April 30, 2025, 10:53:48 amThere is no need to compare NV-19 with these new Chinese developments. NV-19's schematic and software have been improved and improved over the years, and ZT-DQ01 and ZT-DQ02 are still very raw products that Zoyi has been releasing like hot cakes lately.It's good if they listen to user feedback and establish customer feedback, but unfortunately this has not been observed so far.

author: Propretor
author_rank: Regular Contributor
timestamp: April 30, 2025, 11:49:24 am
content: Quote from: indman on April 30, 2025, 11:17:26 amI didn't compare them. Moreover, I am well aware of the history of the creation of these tweezers. I was only surprised by the phrase of our Chinese friend.By the way you have your own very good developer - the creator of M63 Stepan Mironyuk. Also an excellent in-circuit ESR meter. I have it in my “equipment park” and use it often. Stability and accuracy of readings are excellent! A unique product, though with a “primitive” look. But it's like the joke: “Do you want a cab or a ride?”

author: Propretor
author_rank: Regular Contributor
timestamp: April 30, 2025, 11:51:24 am
content: Quote from: daisizhou on April 30, 2025, 11:18:08 amWhich Russian LCR tweezers are you referring to? Apart from the one named above (NV-19) I don't know any other Russian measuring tweezers. And where did you get this information from?

author: ass20
author_rank: Regular Contributor
timestamp: April 30, 2025, 11:54:36 am
content: Hm DQ2 can not measure Inuctance lower 1uHAnd i If you measure capacitor 470uF and morу on 100kHz it is show bad values..

author: Propretor
author_rank: Regular Contributor
timestamp: April 30, 2025, 12:02:40 pm
content: Quote from: ass20 on April 30, 2025, 11:54:36 amFor capacitance measurements of 470µF, 120Hz is used to measure capacitance, and 100kHz is used to measure ESR.

author: Propretor
author_rank: Regular Contributor
timestamp: April 30, 2025, 12:05:41 pm
content: What is HRM-10? Russian measuring tweezers?I only know Fnirsi HRM-10.

author: ass20
author_rank: Regular Contributor
timestamp: April 30, 2025, 12:06:42 pm
content: Quote from: Propretor on April 30, 2025, 12:02:40 pmI check 470uF on DE5000 and ZT-DQ2 DE 5000 show OL (said i can not mesure) But DQ2 show any wrong Values... Why it is do not show OL . do not know

author: Propretor
author_rank: Regular Contributor
timestamp: April 30, 2025, 12:17:34 pm
content: There are 2 approaches by manufacturers - either display the OL or at least show something, albeit roughly. Whichever is closer.

author: coromonadalix
author_rank: Super Contributor
timestamp: April 30, 2025, 12:19:54 pm
content: Quote from: daisizhou on April 30, 2025, 11:59:52 amoh okay they say Zoyi copied the battery impedance measurements, sure if the design is somewhat open

author: ninodeves
author_rank: Contributor
timestamp: April 30, 2025, 12:24:54 pm
content: I bought a Zoyi ZT-DQ02 and I tried to open it, but I couldn't. I removed the four screws, but it still doesn't work and seems stuck. Can anyone give me a solution? I'd like to see the status of the internal battery. Thanks.

author: indman
author_rank: Super Contributor
timestamp: April 30, 2025, 01:12:54 pm
content: Quote from: Propretor on April 30, 2025, 12:17:34 pmWhen the "OL" is on display, the manufacturer is playing fair and that's the right thing to do. When something approximate is shown on the display, it almost always misleads the user, especially a beginner.What's the point of 5 decimal places if the last 2 or 3 of them represent a random number generator?It's better to tell the truth and show "OL" than to cheat by showing a lot of numbers on the display.

author: coromonadalix
author_rank: Super Contributor
timestamp: April 30, 2025, 01:27:33 pm
content: Quote from: ninodeves on April 30, 2025, 12:24:54 pmyou have case snaps/locks around middle length, very hard to pop them out when brand new / never opened

author: coromonadalix
author_rank: Super Contributor
timestamp: April 30, 2025, 01:30:22 pm
content: for the price, i did buy knowing since it's new on the market, it could be a dud, a non finished, nor a polished productthat's why i rely on others equipment(s) too loll

author: Propretor
author_rank: Regular Contributor
timestamp: April 30, 2025, 03:09:15 pm
content: Quote from: indman on April 30, 2025, 01:12:54 pmThat is your opinion and you are entitled to it. But the developer of the NV-19 tweezers, for example, thinks otherwise. I like the precision, too. But, sometimes, I'd rather have the device show 50000µF +-2000µF than OL.

author: indman
author_rank: Super Contributor
timestamp: April 30, 2025, 03:18:41 pm
content: Propretor,We're talking about a few different concepts.The measuring range of the device, the resolution, the measurement error and the accuracy of measurements are slightly different concepts and meanings, aren't they? You should understand this well and distinguish between them, since you are no longer a beginner. The developer of the NV-19 tweezers understands this well.

author: Propretor
author_rank: Regular Contributor
timestamp: April 30, 2025, 03:18:46 pm
content: Quote from: coromonadalix on April 30, 2025, 01:27:33 pmCan the latches be broken?

author: Propretor
author_rank: Regular Contributor
timestamp: April 30, 2025, 03:21:16 pm
content: Quote from: indman on April 30, 2025, 03:18:41 pmNevertheless...

author: indman
author_rank: Super Contributor
timestamp: April 30, 2025, 03:50:58 pm
content: Quote from: daisizhou on April 30, 2025, 12:05:14 pmYou can copy everything you want, but it does not mean that the copy will work just like the original!This can be well seen on the example of a well -known project of transistors testers. How many copies of this project have already been issued by Chinese friends based on more modern and high -speed controllers, but not one of them has not even come close to stable work as the original on Atmega AVR. In addition, in Chinese copies of inexpensive tweezers, circuitry is greatly simplified.

author: ninodeves
author_rank: Contributor
timestamp: May 01, 2025, 09:17:32 am
content: Quote from: coromonadalix on April 30, 2025, 01:27:33 pmThank you very much. I thought it was difficult to open. I'll try more carefully. I just want to make sure the internal battery is in good condition. Regards.

author: ninodeves
author_rank: Contributor
timestamp: May 01, 2025, 12:34:37 pm
content: all this morning I have been using my zoyi zt-dq02 and the truth is I like it a lot and it works very well for how cheap it cost me, only €67 although days later they raised it to €88, I have been comparing it with my DEER DE-5000 and the differences are minimal and unnoticeable, it is not a bad meter, of course it is not a professional meter but to know if a capacitor is bad or not it is more than enough and the data it provides are real and good, the resistance measurement is also very good, I have not been able to compare the coils yet, greetings.

author: kwass
author_rank: Frequent Contributor
timestamp: May 07, 2025, 02:28:35 pm
content: Quote from: Serg65536 on April 26, 2025, 04:03:38 pmI just upgraded from v1.0.5 to v1.0.6 and can confirm that this resolution bug is NOT fixed.

author: ninodeves
author_rank: Contributor
timestamp: May 07, 2025, 08:01:51 pm
content: Quote from: kwass on May 07, 2025, 02:28:35 pmwhere can I get version 1.0.6, thanks.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 07, 2025, 08:10:51 pm
content: read a few pages back and check i posted the files

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 07, 2025, 08:18:59 pm
content: I wanted to try one of these for fun...not gonna happen. 🤦

author: coromonadalix
author_rank: Super Contributor
timestamp: May 08, 2025, 01:35:32 am
content: wuuut wtf ? i dont know if ordering from Canada and push it to USA would be less expensive ?

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 08, 2025, 04:35:14 am
content: Quote from: coromonadalix on May 08, 2025, 01:35:32 amDepends on whether or not there are tariffs from Canada that day. 🤦

author: ninodeves
author_rank: Contributor
timestamp: May 08, 2025, 10:54:50 pm
content: Quote from: KungFuJosh on May 08, 2025, 04:35:14 amWhat a joke the subject of tariffs is

author: ninodeves
author_rank: Contributor
timestamp: May 08, 2025, 10:56:43 pm
content: Quote from: coromonadalix on May 07, 2025, 08:10:51 pmThanks, I have updated to version 1.0.6 and I don't see any significant changes.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 09, 2025, 12:55:33 am
content: Quote from: ninodeves on May 08, 2025, 10:54:50 pmThe joke is the moron making the tariffs, but we don't really need to discuss that here.

author: strannic
author_rank: Newbie
timestamp: May 09, 2025, 01:22:34 pm
content: This is on all ranges - the value reaches 79999 and then resets to 8000, 9000, etc. That is, this tester has a maximum value of 79999 readings.

author: Propretor
author_rank: Regular Contributor
timestamp: May 11, 2025, 03:35:40 pm
content: Zoyi ZT-DQ02:Level 0.6VMode Amp,V RMS,V Frequency,HzR,L,С 0.82 0.570 100, 120R,L,С 0.86 0.612 1kHzR,L,С 0.76 0.540 10kHzR,L,С 0.74 0.524 100kHzLevel 0.3VMode Amp,V RMS,V Frequency,HzR,L,С 0.408 0.292 100, 120R,L,С 0.424 0.305 1kHzR,L,С 0.368 0.271 10kHzR,L,С 0.360 0.261 100kHzLevel 0.1VMode Amp,V RMS,V Frequency,HzR,L,С 0.148 0.099 100, 120R,L,С 0.150 0.102 1kHzR,L,С 0.130 0.090 10kHzR,L,С 0.120 0.088 100kHz

author: BillyO
author_rank: Super Contributor
timestamp: May 12, 2025, 07:37:48 pm
content: Quote from: ass20 on April 30, 2025, 11:54:36 amDid you not read the specifications before buying it?That it cannot measure inductance lower than 1uH is clearly specified.That it will not properly measure a 470uF cap at 100kHz is also clearly specified. Above 1uF, 1kHz is the highest frequency supported.RTFM!!!

author: BillyO
author_rank: Super Contributor
timestamp: May 12, 2025, 07:44:02 pm
content: Quote from: KungFuJosh on May 09, 2025, 12:55:33 amThe moron making the tariffs got spanked by the Chinese and he announced today that he's reduced the tariffs to 30% or so. I imagine he'll get spanked again when they start selling off their bonds for pennies on the dollar. What theorange goo-ball of dungdoes not seem to understand, is that China is the 2nd largest owner of American debt. They can ruin the US in a single day. He better also lay off the Japanese. They own even more than China.Okay, I'll get off my grandstand..

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 12, 2025, 09:13:32 pm
content: Quote from: BillyO on May 12, 2025, 07:37:48 pmNo offense to anybody, but measuring a 470µF cap at 100kHz shows more reading is needed beyond TFM. Usually, the only time a high value cap like that is measured at 100kHz might be for ESR, but the capacitance value is garbage.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 12, 2025, 09:43:13 pm
content: I didn't have a 470µF next to me, so here's a 1mF cap measured on a Hioki IM3570 with an L2000 kelvin probe.You can see the measurements above 1kHz are garbage except ESR. You can't expect a $72 meter toperform magicthat professional equipment can't do.

author: BillyO
author_rank: Super Contributor
timestamp: May 12, 2025, 10:00:30 pm
content: You got to love the negative capacitance though. It's what makes faster than light travel possible.

author: Martin72
author_rank: Super Contributor
timestamp: May 12, 2025, 10:06:36 pm
content: QuoteThat's the main point.The circuit topology alone cannot deliver that for so little money; there really are limits.Then:In order to be able to check the performance/“credibility” of a meter to some extent, you should use components for measurement for which data sheets are available.These data sheets usually contain the test specifications, for example, the frequency at which the value was determined.Then you can see whether your own measuring device comes to the same result.That's what I would do first.Then there is the point Josh briefly mentioned: realistic measurement conditions.When measuring a high-capacity capacitor at high frequencies, you have to be careful about what you see on the display.

author: aiekszzz
author_rank: Newbie
timestamp: May 13, 2025, 05:03:05 am
content: Principles of LCR meter measurement.Operating frequencyDuring operation, the meter supplies an AC test signal to the test device.Frequency is one of the main parameters of an alternating current source. Due to the fact that the component parameters differ from the ideal ones and are distributed, as well as due to the influence of distributed parameters on the input contacts, different results can be obtained for the same component with different operating frequency values. Therefore, choosing the right operating frequency is important.Serial (Ser) and Parallel (Par) connection modesSelecting an appropriate equivalent mode can improve the measurement result. The serial mode is more suitable for elements with low impedance (<100 ohms), and the parallel mode is more suitable for elements with high impedance (>10 kOhms).For elements with an impedance between these two values, the equivalent mode does not have much effect on the measurement result.Capacity measurement:1. It is advisable to measure a small capacity in Parallel connection and with an increased measurement frequency.2. It is advisable to measure high capacity in a serial connection (Series) and at a reduced measurement frequency.Measurement of inductance:1. It is advisable to measure low inductance in a serial connection (Series) and an increased measurement frequency.2. It is advisable to measure a large inductance in parallel connection and a lower measurement frequency.

author: aiekszzz
author_rank: Newbie
timestamp: May 13, 2025, 05:49:55 am
content: I have an ET432 East Tester and a curiosity-bought ZTDQ 02. What I liked about the ZTDQ 02 is that it saves the parameters after switching off and the calibration is done once for specific probes. The ET432 East Tester needs to be calibrated every time it is turned on. I calibrated the ZTDQ 02 to Kelvin in closed and open mode. I didn't touch the other parameters.The calibration function is used for open and closed circuits. Calibration reduces the error caused by the parameters of the test line.Short-circuit calibration reduces the effect of probe resistance when measuring low-resistance components.Open circuit calibration can reduce the effect of distributed capacitance and resistance between two points of the test line when measuring the parameters of components with high impedance.These are the measurement accuracy parameters for the East Tester ET432. From this it can be seen that by measuring a large capacity at a frequency of 100kHz on a particular device, the accuracy can jump out in 10-20%.Why ZOYI did not provide such tables for its product remains a mystery.

author: Martin72
author_rank: Super Contributor
timestamp: May 13, 2025, 07:31:04 am
content: QuoteWant to take three guesses, or is one enough?

author: Propretor
author_rank: Regular Contributor
timestamp: May 13, 2025, 08:12:21 am
content: Manual in English.

author: aiekszzz
author_rank: Newbie
timestamp: May 13, 2025, 08:19:37 am
content: Quote from: Martin72 on May 13, 2025, 07:31:04 amThis is more of a rhetorical questionFor 60 bucks, it's a good hobby device, but the wires go straight to the trash.

author: aiekszzz
author_rank: Newbie
timestamp: May 13, 2025, 08:30:21 am
content: If you're interested, I can post a comparison of several measurements on ZOYI and ET432.

author: Martin72
author_rank: Super Contributor
timestamp: May 13, 2025, 08:38:50 am
content: QuoteWhich also explains why measuring 470µF with 100kHz does not make sense.

author: Propretor
author_rank: Regular Contributor
timestamp: May 13, 2025, 09:01:30 am
content: Quote from: aiekszzz on May 13, 2025, 05:49:55 am

author: Propretor
author_rank: Regular Contributor
timestamp: May 13, 2025, 09:03:10 am
content: Martin72 Beat me to itNo one has received the new firmware 1.07 yet?

author: Aldo22
author_rank: Super Contributor
timestamp: May 13, 2025, 09:08:35 am
content: Maybe I haven't understood something fundamental, but I've been wondering the same thing about my ZT-MD1:If you look at this data, the best accuracy is always at 1kHz. Why should you change the frequency at all?

author: aiekszzz
author_rank: Newbie
timestamp: May 13, 2025, 09:45:47 am
content: moreover, all the ratings shown on the schematic diagrams and on the radio components for the frequency of 1kHz

author: Propretor
author_rank: Regular Contributor
timestamp: May 13, 2025, 10:58:09 am
content: Quote from: aiekszzz on May 13, 2025, 09:45:47 amWhere did you get that information? I know that premium manufacturers of quality electrolytic capacitors specify ESR at 100kHz in their documentation. Moreover, considering the spectrum of pulse converters, it is the ESR value at 100kHz that is more important than at 1kHz or 10kHz.

author: indman
author_rank: Super Contributor
timestamp: May 13, 2025, 11:06:56 am
content: Quote from: Aldo22 on May 13, 2025, 09:08:35 amLet's make it easy for the manufacturer and ourselves. They will produce LCR bridge meters with only one 1kHz frequency. That's fine!Then why would I need a DE-5000 or other similar $70-100$ units? The same basic parameters of LCR I will perfectly measure on a transistor tester for 10$ or with a sound card for 5$ and a computer. And the results, believe me, will not differ much from expensive devices for 1000$.

author: aiekszzz
author_rank: Newbie
timestamp: May 13, 2025, 11:26:03 am
content: Quote from: Propretor on May 13, 2025, 10:58:09 amI was referring to the main parameters - capacitance and inductance.When you buy an inductor, do you ask for 22mH at 100kHz 5A or just say 22mH 5A?And on the basic electrical diagram, for which frequency are the parameters given?

author: Propretor
author_rank: Regular Contributor
timestamp: May 13, 2025, 11:30:33 am
content: Quote from: aiekszzz on May 13, 2025, 11:26:03 amBased on your response you are telling the seller: “please sell me an inductance of 22mH at 1kHz 5A”.

author: indman
author_rank: Super Contributor
timestamp: May 13, 2025, 11:41:14 am
content: Most recently, I really liked the response of a forum participant respected by many radio amateurs КРАМhttps://radiokot.ru/forum/viewtopic.php?p=4713975#p4713975For Russian-speaking forum participants, this link will be enough, but I do not yet know how to convey its meaning in English.

author: aiekszzz
author_rank: Newbie
timestamp: May 13, 2025, 11:57:13 am
content: Yes, I already realized that I was severely blunted. Confused with the reactance

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 13, 2025, 02:59:35 pm
content: Quote from: KungFuJosh on May 12, 2025, 09:43:13 pmQuote from: Propretor on May 13, 2025, 10:58:09 amYou need to read datasheets for devices you're testing.A datasheet might say something is rated at 100kHz for ESR, but the actual capacitance value is+/- 20% at 120Hz.In this case, that means:To match datasheet ESR, you test at 100kHz.To match datasheet CAPACITANCE, you test at 120Hz.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 13, 2025, 03:40:08 pm
content: exactly

author: mawyatt
author_rank: Super Contributor
timestamp: May 13, 2025, 03:40:20 pm
content: Many of these newer LCR Meters, Tweezers, Handhelds or Bench types, employ the Auto-Balance LCR Architecture where the DUT voltage and current are measured and the DUT complex impedance computed from such.This architecture uses a scaled Transimpedance Amp to measure the DUT Current in a "Virtual Ground" configuration in which DUT current is supplied by the meter source thru a controlled source resistance. The meter must supply the source DUT current as well as sink this current thru the Transimpedance amp, which places demands on the meter circuitry to handle these high currents at higher frequencies for low Z DUT devices.Low DUT Z requires significant DUT current to produce an acceptable DUT voltage for measurement. If one considers DUT Capacitive Impedance @ 100KHz, this equates to ~1.6uΩ/Farad DUT Z. So a 160uF Cap only has ~10mΩ impedance and with a high test source current of 100ma only produces 1mv DUT voltage. Here a 1KHz measurement makes more sense as the resultant DUT voltage now becomes 100mv and much easier to accurately resolve. Conversely an inductance follows the opposite, for example a 1.6uH inductance has an impedance at 1KHz of 10mΩ and the measurement would benefit from using 100KHz as the impedance increases to 1000mΩ.Consider having an LCR meter capable of delivering higher source (and sink) currents at higher (and lower) frequencies if Low Z DUTs are involved, and comes as no surprise that Tweezers, Handhelds and lower cost Bench Meters where battery and or cost become major factors, have limited frequency and DUT impedance ranges.Anyway, hopefully this illustrates the importance of knowing how these meters operate, the limitations, and how the DUT characteristics must be considered when making quality measurements.In all cases KTI (Know Thy Instrument) is a requirement for better measurementsBest

author: Martin72
author_rank: Super Contributor
timestamp: May 13, 2025, 04:46:15 pm
content: Wise words, as always from Mike.It should also be noted that with the tiny voltages mentioned, there is a risk that some of them will be “lost” in the circuit's inherent noise and lead to falsified measurement results—this is particularly noticeable with inexpensive LCRs, sometimes even at frequencies as low as 10 kHz.Because it's important to remember that all the parameters that are available and can be displayed are calculated values based on the measured impedance.And if that's already questionable at higher frequencies, everything else is questionable too.In addition, there are components that cannot be measured accurately, even with more expensive equipment, because the currents/voltages are too low.At work, when we measure/adjust filter chokes, we use a device we built ourselves that can provide currents of up to 200A in pulses.This allows us to reach the range where the choke in the device operates.Of course, this won't happen to everyone, but it was just an example to show that even very expensive devices can reach their limits.

author: mawyatt
author_rank: Super Contributor
timestamp: May 13, 2025, 05:10:29 pm
content: Yeah, noise is always an issue as is accuracy (seems to decrease as the DUT impedance drops), which is also an issue with properfilteringfixturing which is another separate topic.200A, that's certainly well beyond any LCR meter we're aware of!!Best

author: mawyatt
author_rank: Super Contributor
timestamp: May 13, 2025, 05:36:53 pm
content: One of the interesting things about these handheld LCR meters is the use of the slotted H and L openings for leaded component use. This provides a direct really nice means for 4 wire Kelvin measurements where the DUT leads make the Kelvin Connections between Force and Sense. Bench type LCR meters require a special Fixture to translate the 4 BNCs to the slotted capability of the handhelds.Low Z SMD DUTs pose a difficult measurement for both handhelds and bench types and why we developed the "Split-Kelvin" fixtures shown here:https://www.eevblog.com/forum/projects/different-type-lcr-smd-fixture/These improve low Z SMD results, and folks with bench type LCR meters should consider this technique. Note we even developed a version for Bench DMMs, which also works quite wellBest,

author: Martin72
author_rank: Super Contributor
timestamp: May 13, 2025, 07:12:05 pm
content: Quote from: mawyatt on May 13, 2025, 05:10:29 pmHere is an example measurement, albeit with “only” approx. 22A...That was in the preliminary stage; the device can measure/calculate/display the values itself.To get back to the topic, here are two pictures of the inner workings of LCRs.Even though the packing density is getting higher and higher, you can see at first glance that one of them was designed to be much more complex and should “work better,” but that comes at a price.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 13, 2025, 07:57:31 pm
content: You're missing a PCB in that Hioki photo that costs more than the ET meter. 😉

author: Propretor
author_rank: Regular Contributor
timestamp: May 13, 2025, 08:34:17 pm
content: QuoteYour words don't contradict what I wrote earlier. In fact, I agree with them. It's just that you supplemented my words with information about capacitance measurement. I just limited myself to mentioning ESR.

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 13, 2025, 08:55:56 pm
content: Quote from: Propretor on May 13, 2025, 08:34:17 pmI simply added clarity for people who can't extrapolate the rest of the information from your statement. 😉

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 13, 2025, 09:06:37 pm
content: The tariff got a little better. The totally price is now lower than the tariff was, but it's still too high.

author: Martin72
author_rank: Super Contributor
timestamp: May 13, 2025, 09:28:41 pm
content: Quote from: KungFuJosh on May 13, 2025, 02:59:35 pmThe meter will display an ESR value, with the capacity measured in the calculation at 100 kHz.However, if the meter is unable to measure accurately at 100 kHz due to its low-cost design, the ESR value displayed at 100 kHz will also be inaccurate.You can compare the measured values at 120 Hz to see if the values at 100 kHz are “correct.”It is best to test the meter with a component that has been thoroughly documented.

author: andre3d
author_rank: Contributor
timestamp: May 14, 2025, 02:05:20 am
content: Firmware v1.0.7 for ZT-DQ02https://zotektools.com/products/zoyi-zt-dq02/

author: coromonadalix
author_rank: Super Contributor
timestamp: May 14, 2025, 02:16:38 am
content: remove the dot TXT extension

author: ninodeves
author_rank: Contributor
timestamp: May 14, 2025, 12:16:11 pm
content: Quote from: andre3d on May 14, 2025, 02:05:20 amthank you so much.

author: ninodeves
author_rank: Contributor
timestamp: May 14, 2025, 12:17:49 pm
content: Quote from: coromonadalix on May 14, 2025, 02:16:38 amthank you so much.

author: ninodeves
author_rank: Contributor
timestamp: May 14, 2025, 12:20:33 pm
content: I've been using my Zoyi meter for a few days now and I'm not unhappy with it. It's more than enough for my repairs. For more professional tasks, it's clearly not very reliable. However, to know if a capacitor is good or bad, a resistor is good, or a coil is in perfect condition, it's sufficient, and for its price, it's the best thing that's ever happened to me. Regards.

author: Propretor
author_rank: Regular Contributor
timestamp: May 15, 2025, 08:11:13 am
content: Who saw what changes after upgrading to firmware 1.07?

author: ninodeves
author_rank: Contributor
timestamp: May 15, 2025, 11:21:56 am
content: It seems to be faster in measurements, but there isn't much difference, at least I haven't noticed anything special.

author: andre3d
author_rank: Contributor
timestamp: May 15, 2025, 12:09:11 pm
content: On the forum crystalradio.cn writes "Firmware to support CDR measurements is said to be available in May this year."http://www.crystalradio.cn/thread-2188559-6-1.html

author: Propretor
author_rank: Regular Contributor
timestamp: May 15, 2025, 12:38:06 pm
content: Quote from: andre3d on May 15, 2025, 12:09:11 pmWhat is CDR?

author: andre3d
author_rank: Contributor
timestamp: May 15, 2025, 12:48:16 pm
content: Probably DCR 0Hz.

author: Propretor
author_rank: Regular Contributor
timestamp: May 15, 2025, 05:54:11 pm
content: With firmware 1.0.7 there is also no DCR mode.

author: aiekszzz
author_rank: Newbie
timestamp: May 16, 2025, 03:34:51 am
content: Does everyone have a voltmeter by default, has different readings in forward and reverse polarity and requires calibration? And the battery calibration mode does not work in closed mode.I checked it out. Glitches with the battery tester are in the firmware ZT-DQ02_v107. 106 everything works fine

author: coromonadalix
author_rank: Super Contributor
timestamp: May 16, 2025, 11:54:09 am
content: i think they have put this one in the market too fast and not properly tested ?

author: ninodeves
author_rank: Contributor
timestamp: May 18, 2025, 06:53:43 pm
content: Hello colleagues, has anyone else updated their Zoyi DQ02 to version 1.0.7? I have tried measuring the battery resistance and it does not work. I have tried going back to version 1.0.6, which was previously working, and it still does not work. Can anyone try this on their DQ02 to see if it works for you or if it only happens to mine? The other functions work perfectly. Best regards.

author: i.shadrin
author_rank: Contributor
timestamp: May 19, 2025, 01:34:20 pm
content: Quote from: tszaboo on April 08, 2025, 07:48:53 pmJust bought UT622E for 300+$

author: ninodeves
author_rank: Contributor
timestamp: May 19, 2025, 08:27:32 pm
content: Quote from: ninodeves on May 18, 2025, 06:53:43 pmI turned it back on and as if by magic it started measuring batteries and battery resistance again. Regards.

author: ninodeves
author_rank: Contributor
timestamp: May 19, 2025, 08:30:24 pm
content: Quote from: i.shadrin on May 19, 2025, 01:34:20 pmIt's a good meter, but for $300, in my opinion, there are better ones, such as the PeakTech 2170.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 20, 2025, 02:19:21 am
content: before suggesting check some teardowns of some lcr'sthe Peaktech 2170 is a 2 chip solution like the De-5000, or similar Cirustek chipsetshttps://www.eevblog.com/forum/reviews/some-photos-from-a-peaktech-2170-teardown/we already know a few models and brands with theses ic'sUT-612 not he 622 series, DE-5000, peaktech 2170, mastech ms5308 ...pls this is a thread about the Zoyi ZT-DQ01 and ZT-DQ02

author: andre3d
author_rank: Contributor
timestamp: May 29, 2025, 12:09:30 pm
content: New firmware v1.0.81. Add low milliohm interference bottom number reset, 2. Add large measurement inductance range switching promptdel ".txt"

author: Propretor
author_rank: Regular Contributor
timestamp: May 29, 2025, 12:51:26 pm
content: Quote from: andre3d on May 29, 2025, 12:09:30 pmWhat source is the firmware from?

author: andre3d
author_rank: Contributor
timestamp: May 29, 2025, 01:02:26 pm
content: Source:http://www.szzotek.com/h-col-159.html

author: coromonadalix
author_rank: Super Contributor
timestamp: May 29, 2025, 03:56:59 pm
content: both are 1.08 ??

author: andre3d
author_rank: Contributor
timestamp: May 29, 2025, 04:04:49 pm
content: Yes seehttps://www.eevblog.com/forum/testgear/new-lcr-meters-zoyi-zt-dq01-and-zoyi-zt-dq02-(march-2025)/msg5929764/#msg5929764

author: andre3d
author_rank: Contributor
timestamp: May 29, 2025, 04:16:44 pm
content: Comment from mydigit.cnDQ01 02 has upgraded the firmware.1. Added the function of clearing small resistors, inductors and capacitors.2. Fixed the problem of incorrect automatic range measurement of 5 to 6 resistors.3. The value of the screening function has been increased from 0 to 9 repeat cycles.Upgrading this firmware requires recalibration of the three short-circuit resistors of 10 milliohms, 100 milliohms and 1Ω.source:https://www.mydigit.cn/thread-522984-1-1.html

author: dmitrkov
author_rank: Contributor
timestamp: May 30, 2025, 05:49:42 am
content: Quote from: andre3d on May 29, 2025, 04:16:44 pmWhat the hell... Here again we need calibration after firmware update. It happened before with MD1

author: KungFuJosh
author_rank: Super Contributor
timestamp: May 30, 2025, 12:11:14 pm
content: Quote from: dmitrkov on May 30, 2025, 05:49:42 amOn a real LCR, open/short calibration is needed frequently. This toy needing it after a firmware upgrade isn't very exciting.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 30, 2025, 12:42:35 pm
content: just a matter of getting theses parts ... i would not criticizes as much, but if the warning is issued, it's better than not knowingto me having a possibility to calibrate is better than nothing, or not having the possibility of doing it yourself ?still happy with itjust try to calibrate an Sencore lc102 .... you have at least 25-26 trimpots in it , and need much more materials to do so, loll

author: jebem
author_rank: Regular Contributor
timestamp: June 10, 2025, 02:05:18 pm
content: Thank you for the info on the firmware links.It seems that the old Zotek website is going down and the link to download the firmware is not available anymore as indicated above (http://www.szzotek.com/h-col-159.html).And the new website allows to download the firmware for v1.07 only. athttps://zotektools.com/products/zoyi-zt-dq02/Older versions and the new v1.08 are not offered there.

author: RAPo
author_rank: Super Contributor
timestamp: June 10, 2025, 02:08:47 pm
content: I got a virus warning on that site.

author: jebem
author_rank: Regular Contributor
timestamp: June 10, 2025, 02:15:27 pm
content: Quote from: RAPo on June 10, 2025, 02:08:47 pmWhen i connect to the old website, I get a administrative msg with:"Sorry, the page you visited does not exist!Please double check that the URL you entered is correct.Home page"

author: jebem
author_rank: Regular Contributor
timestamp: June 10, 2025, 02:21:47 pm
content: Quote from: RAPo on June 10, 2025, 02:08:47 pmOn a second look, it seems that the old Chinese website uses a non secure connection, and that is a good reason to trigger alerts on security tools.

author: zappa916
author_rank: Newbie
timestamp: June 11, 2025, 07:12:08 am
content: g'dday folks,New subscriber here and caught onto this thread cause im in the market for a LCR. I currently have a 3-1 Zoyi dvm oscilloscope and reading whether the DQ01 or 02 is worthy to grab. It's either that or the DE-5000, with the ET431 running close behind. What's the consensus so far?

author: jebem
author_rank: Regular Contributor
timestamp: June 12, 2025, 07:06:04 pm
content: Quote from: zappa916 on June 11, 2025, 07:12:08 amI have ordered one ZT-DQ02 from AliExpress and payed just 71 EUR including shipment as it was on sale. Now it went up to 99 EUR.It is coming may way and I expect to receive it in a few days.This seems to be a low cost LCR meter with nice specifications on paper that would compete with other brands costing two or four more times.From what I have been reading from testers on published videos and reviews, it may present a few bugs and quirks.At the same time, it seems to be very precise when it operates outside the buggy zone, fulfilling the advertised specs.However, these tests seems to have been done in a kind of random way, without a systematic approach, or in a controlled environment.Still, they are very useful specially when they compare it side by side with other brands running the same measurement.Some of the testers compare it to the DE-5000 (costing twice the price of the ZT-DQ02) or to the Tonghui TH2822D (costing more than four times).The results seems to be basically similar.However, for the (random) tested components done by the testers in those reviews, the ZT-DQ02 shows some erratic results, while the other brands don't.As an example, this Chinese review shows some of these issues. He compares it to the TH2822D used as a reference.https://www.bilibili.com/video/BV1JfLczdEnu/?t=0.0Can I live with the observed issues?Yes, except for the 10MR reading that the ZT-DQ02 can't acquire correctly, no matter what settings the tester tried.He didn't test resistors above 10MR either (at least on that video recording).And he didn't calibrate the LCR meter, nor did a reset to factory defaults (as indicated in the user guide) to see the result.The above video was posted on 20-April-2025, so he was probably running version 1.05.Zotek / ZOYI have released several firmware versions after that, where the latest v1.08 is dated as of 29-May.So, we don't know if the reported issues have been fixed.

author: coromonadalix
author_rank: Super Contributor
timestamp: June 12, 2025, 08:11:35 pm
content: IF Zoyi is putting the efforts getting the FW bugs ironed out, it may get better at some point, i dont think perfection is possible, well know lollDe 5000 never got any fw updates if any, or possible, others i dont know, the Hantek 1832 1833 did receive some, there's a tons of handhelds out thereNone so far received as much attention than this one 1.05 1.06 1.07 1.08 all under a 4-6 month period ... maybe they slow down, stop trying to impress us ? would be nice to get a log of all the updates since 1.05if you can live with some quircks, good, do keep in mind they are not bench ones, some brands have better specs in some measurement, all rely on circuits, designs, firmwares quality and frequent updates, alas not all of them do that...I'm not a Zoyi fan boy, it's my 1st from them

author: TheDefpom
author_rank: Frequent Contributor
timestamp: June 14, 2025, 04:14:05 am
content: Zoyi sent me a DQ02 to review, I just got it in the mail so I will be doing a review video on it sometime in the next few weeks.

author: LeonR
author_rank: Regular Contributor
timestamp: June 16, 2025, 08:53:40 pm
content: Seems like there's a rebrand from ANENG, as LM06 (DQ01) and LM08 (DQ02).https://www.aliexpress.com/item/1005009173709248.htmlWeird enough, the "pro" version of those don't include the Kelvin clips, just the standard (on their multimeters) extra pair of test leads.

author: jackobo
author_rank: Contributor
timestamp: June 16, 2025, 08:57:24 pm
content: folks, DQ-02 at its top kit with all leads about 60 euro now using summer sale discount coupon at aliexpress with free postage.

author: coromonadalix
author_rank: Super Contributor
timestamp: June 16, 2025, 09:16:39 pm
content: Quote from: LeonR on June 16, 2025, 08:53:40 pmlol now Aneng branded, funny to see a suggested price wayyyy higher than sold, psychological effect of saving tons of $the pro kit is not worth it, just shi#$^^ probes kit .... for the kelvins, some threads back you have a good compatible kit

author: dmitrkov
author_rank: Contributor
timestamp: June 17, 2025, 06:15:16 am
content: Perhaps someone else will also find it useful. I bought calibration resistors herehttps://www.aliexpress.com/item/1005008077044186.htmland herehttps://www.aliexpress.com/item/1005008113029467.html.I'm not sure if they are really 0.1%. But the seller assures me that they are. 2 out of 10 came with W(0,05%) instead of B(0,1%).The meter without recalibration on firmware 1.0.5 shows everything within tolerance except the 10M nominal valuePhotos:https://photos.app.goo.gl/gk8tEHPHLLxBcvFo7

author: Propretor
author_rank: Regular Contributor
timestamp: June 17, 2025, 05:20:15 pm
content: Quote from: dmitrkov on June 17, 2025, 06:15:16 amManual:Notes:a.Use non-inductive resistors for calibration. Do not use wound resistors.

author: coromonadalix
author_rank: Super Contributor
timestamp: June 17, 2025, 06:36:51 pm
content: and the ones @dmitrkov used are non inductive .... witch is supposed to be good@dmitrkov have you tried with the latest FW version ?

author: ass20
author_rank: Regular Contributor
timestamp: June 17, 2025, 08:40:31 pm
content: anybody open ali disput for additional send clibration resistors ?zoyi have support ? or it like only our money ?

author: Maksud
author_rank: Newbie
timestamp: June 18, 2025, 01:05:18 pm
content: Updated to version V 1.0.8.I only did short circuit calibration. I checked it on SMD resistors with 1% accuracy and it shows everything within the tolerance.But it doesn't measure 10M resistance at all and that's bad.Buying high-precision resistors doesn't make much sense because the price of a high-precision resistor set will be like half the device. And if someone needs such accuracy, then this device is not for them. IMHOOf the useful things, this is a good Kelvin bridge ZIBOO ZB-L100K (AliExpress product 1005007592063774) (enter the number in the search bar AliExpress)

author: Aldo22
author_rank: Super Contributor
timestamp: June 18, 2025, 04:57:54 pm
content: Would you say that it is worth buying a ZT-DQ01 as a hobbyist, if you already have a ZT-MD1?The specs (ranges) don't differ that much, afaics.What are the advantages? How could I talk myself into it?

author: RAPo
author_rank: Super Contributor
timestamp: June 18, 2025, 05:18:52 pm
content: well I must say the screen of the DQ1 is much better to read. But the real question is, do you need a 4-wire measurment?Quote from: Aldo22 on June 18, 2025, 04:57:54 pm

author: jackobo
author_rank: Contributor
timestamp: June 18, 2025, 05:44:49 pm
content: Quote from: RAPo on June 18, 2025, 05:18:52 pmWell, actually MD-1 is 4 wire measurement as well in tweezers form factor

author: Aldo22
author_rank: Super Contributor
timestamp: June 18, 2025, 06:06:48 pm
content: Thank you!Quote from: RAPo on June 18, 2025, 05:18:52 pmQuote from: jackobo on June 18, 2025, 05:44:49 pmSo would you say that the DQ01 it's a bit more convenient and accurate, but doesn't provide that much more information for the hobbyist than the MD1?Or have I missed something?

author: jackobo
author_rank: Contributor
timestamp: June 18, 2025, 06:11:38 pm
content: Quote from: Aldo22 on June 18, 2025, 06:06:48 pmDQ series provides more features and measurement ranges than MD-1. In terms of precision I'd say them both are +- equal.

author: FixyMixy
author_rank: Contributor
timestamp: June 18, 2025, 06:21:26 pm
content: Quote from: TheDefpom on June 14, 2025, 04:14:05 amIt's VERY important to review1.0.8 firmware!Older firmware does NOT measure all resistors correctly (eg: 6.8-7.4 kOhm, 68-74 kOhm). That is because of a wrong range switching algorithm.For those resistors, the device showed 6% higher resultsfrom time to time in a random but deceptively confident manner.

author: FixyMixy
author_rank: Contributor
timestamp: June 18, 2025, 06:34:04 pm
content: Quote from: Aldo22 on June 18, 2025, 06:06:48 pm4 wire measurement is good for accurate low impedance (below 10 mOhm). That's because of contact resistance fluctuation is excluded from measurement. But DQ01 does has just a 0.1 mOhm resolution in LCR mode.100 kHz is good for low inductance measurement (below 10 uH)See yourself, if you would use that much.

author: Aldo22
author_rank: Super Contributor
timestamp: June 18, 2025, 06:58:07 pm
content: Quote from: FixyMixy on June 18, 2025, 06:34:04 pmYou don't really mean 0.1 mOhm, right?According to the specifications, only the upper limits are different (mF, H).Neither can do nH.10mΩ~10MΩ both1pF~20mF vs. 1pF~100mF1uH~60H vs. 1uH~100H

author: FixyMixy
author_rank: Contributor
timestamp: June 18, 2025, 09:01:40 pm
content: Quote from: Aldo22 on June 18, 2025, 06:58:07 pmMaximum resolution is indeed 0.1 mOhm (though displayed as 0.0001 Ohm) and 0.1 uH (100 nH).

author: Aldo22
author_rank: Super Contributor
timestamp: June 18, 2025, 09:23:22 pm
content: Quote from: FixyMixy on June 18, 2025, 09:01:40 pmYou're right, I got things mixed up.MD1 also has this resolution in the lowest range.

author: Serg65536
author_rank: Regular Contributor
timestamp: June 19, 2025, 04:12:35 am
content: Quote from: Aldo22 on June 18, 2025, 09:23:22 pmMD1 is jumping very much on low impedance measurements. It does NOT have 4 wire contact.

author: dmitrkov
author_rank: Contributor
timestamp: June 19, 2025, 05:44:55 am
content: Quote from: coromonadalix on June 17, 2025, 06:36:51 pmYes, the description says "Non-Inductive". I haven't updated to version 1.0.8 yet. After the update I will check the calibration and look at the inductance of these resistors. I'll write about the result if you are interested

author: Aldo22
author_rank: Super Contributor
timestamp: June 19, 2025, 08:48:05 am
content: OK, I've ordered one. Not because I'm convinced I need it, but because it was very cheap today.53 CHF ($62) total for the ZT-DQ02 with all accessories.I hate myself...

author: RAPo
author_rank: Super Contributor
timestamp: June 19, 2025, 09:27:36 am
content: Don't, the reason for living is to experience, and that is exactly what you are doing now.Keep up the good work.Quote from: Aldo22 on June 19, 2025, 08:48:05 am

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 19, 2025, 02:31:41 pm
content: Quote from: Aldo22 on June 19, 2025, 08:48:05 amWhy? You're on a website with thousands of people that also experience TEAS. I have several LCR meters, including pro bench meters, that aresignificantlybetter than this. The only thing stopping me from buying it is the tariffs. 🤷

author: Aldo22
author_rank: Super Contributor
timestamp: June 19, 2025, 04:12:28 pm
content: @RAPo@KungFuJoshThanks guys! I feel better now.The Chinese aren't sleeping either, the package is already out of the warehouse.

author: Propretor
author_rank: Regular Contributor
timestamp: June 19, 2025, 04:54:37 pm
content: @dmitrkov, @coromonadalix

author: andre3d
author_rank: Contributor
timestamp: June 19, 2025, 06:27:22 pm
content: EE BWL High Precision Resistor 0.1% Low Temperature Coefficient Drift Sampling Non-inductive

author: Atlan
author_rank: Frequent Contributor
timestamp: June 20, 2025, 03:49:58 am
content: Bifilar winding

author: TheDefpom
author_rank: Frequent Contributor
timestamp: June 20, 2025, 05:56:51 am
content: I recorded the DQ02 review video yesterday, it works very well for the price, the battery IR tests agreed with my HP 4338B with good accuracy for instance.I checked it on my resistance standards, GenRad capacitance standards, GenRad decade inductance box, and compared to a couple of my other LCR meters.I plan to publish the video on the 25th, I still have to edit it yet.

author: dmitrkov
author_rank: Contributor
timestamp: June 20, 2025, 01:15:16 pm
content: Quote from: Propretor on June 19, 2025, 04:54:37 pmWell I have already updated the firmware to 1.0.8 and calibrated the positions: 10 mOhm, 100 mOhm, 1 Ohm, 100 kOhm and 10 MOhm with these resistors. I also have smd 0805 resistors of these ratings with 1% and 0,1% accuracy. When measuring these smd resistors with the LCR SMD Test Clip (https://www.aliexpress.com/item/1005002531512011.html), the readings are within tolerance.Also checked the measurements against ET432 and they are the sameI don't know what else could be affected by calibrating the wirewound resistors. The manual also says: For 10mΩ and 100mΩ standard resistors, it is recommended to use PBV 4-wire resistors. But, considering their price and the problem to buy them - it is already too much....To create a non-inductive wire-wound resistor, half of the resistance windings are wound in one direction (say clockwise) then the wire is folded back on itself and the rest is then wound in the opposite direction (say anti-clockwise) These two windings are inductive but the two inductances so created "cancel" each other out (from an inductance viewpoint) whilst the resistance is the value determined by the full length of wire.https://forum.arduino.cc/t/what-is-a-non-inducting-resistor/436610/6

author: Propretor
author_rank: Regular Contributor
timestamp: June 21, 2025, 07:14:08 am
content: @dmitrkov, try to measure the inductance at your calibration resistors, it would be curious...

author: svetlov
author_rank: Regular Contributor
timestamp: June 22, 2025, 10:46:49 am
content: hello! the seller on ali has two options ZTDQ02 and ZTDQ01 what is the difference between them?

author: Aldo22
author_rank: Super Contributor
timestamp: June 22, 2025, 10:50:44 am
content: Quote from: svetlov on June 22, 2025, 10:46:49 amZT-DQ02 has additionally "Battery Internal Resistance Measurement".https://zotektools.com/lcr-tweezers-brigde-tester/

author: Aldo22
author_rank: Super Contributor
timestamp: June 23, 2025, 01:21:16 pm
content: New Video:

author: TheDefpom
author_rank: Frequent Contributor
timestamp: June 23, 2025, 10:54:44 pm
content: I published mine 12 hours earlier than planned...I realised afterwards that I probably should have had the insulating jumper installed the entire time... oh well.

author: Aldo22
author_rank: Super Contributor
timestamp: June 25, 2025, 07:48:31 am
content: Seems to be a new delivery record. Less than 6 days from the time I ordered in Dongguan to my house.FW is 1.0.7. Is it worth upgrading to 1.0.8 (and losing the factory calibration)?Thank you.

author: MultiMan
author_rank: Newbie
timestamp: June 25, 2025, 08:28:28 am
content: Thanks for the great review! The meter behaved better than I expected.I'm an amateur that now at 60 decided to start repair electronics more regularly. In school I was torn between going the engineering/electronics path or the biology/chemistry that I chose as I always was interested in basically everything, so now I'm returning to electronics to try and change things up. Anyway, with that being said, I have a question for the knowledgeable people here:I ordered a DQ02 from Banggood in May and it only arrived after 6 weeks or something, with Chinese only manual and Firmware 1.05. I don't at this time have any precision resistors or any other high precision standards, so what is my best course of action? Use the meter with 1.05 and avoid the affected ranges (have other multimeters) or maybe update to 1.07 , but now I forgot if that fixes the broken algorithm. I would very much appreciate your input.

author: jebem
author_rank: Regular Contributor
timestamp: June 25, 2025, 03:07:26 pm
content: Quote from: Aldo22 on June 25, 2025, 12:25:23 pmHi Aldo,Just checked, my LCR meter shipped with V1.07. I just got it a few days ago and had no chance to evaluate it properly. I have an older Proster BM4070 LCR meter that serves me well, although without the precision offered by the new one.As a general rule, one should calibrate the meter after each FW update, just in case.I believe you can go back to v1.07, but a support call to the maker will probably be safer before proceeding with the rollback.I bought the 0.1% resistors to have a reference to check my meters,especially on the Alientek DM40, and to be able to calibrate testers when needed.Problem is, as you noted, 0.1% is not precise enough if we really want to have the meter "calibrated" assuming the target equipment is precise and accurate enough to differentiate between a piece of wire and a low value resistor.AliExpress sells precision resistors where a single one cost more that the whole lot of ten 0.1% resistors I bought.I accept that 01% is good enough for me, the problem is that I can't be sure that all my 0.1% resistors are within the advertised tolerance.What is the difference between a 0.01R resistor and a piece of wire?Well, if the LCR meter is precise/accurate enough it will show the difference.Different wire materials (leagues) and geometry (section, number of cores) have different resistivity and final resistance per length unit, and it will also impose a unique fingerprint in the form of parasitic inductance and capacitance.In addition, each meter these days will have its own interpretation of reality, depending on the algorithm in use to "iron out" obvious wrong readings.As an example, my DQ-02 will give kind of erratic values on low ohm measurements when using a 23 EUR Ziboo Kelvin test leads, while the stock included Kelvin leads will give almost stable readings (only the last digit keeps changing).The above error varies depending on the used frequency and even changing level will result in reading changes.See pictures. I believe this is related to the excessive inductance/capacitance of the Zeboo leads that the DQ02 firmware is not prepared to handle.

author: Atlan
author_rank: Frequent Contributor
timestamp: June 25, 2025, 04:17:07 pm
content: I don't know if it is appropriate to achieve an accuracy of 0.1% of resistances with a measuring device for 80E (Chinese). When the result will be measured resistances of 5% and 1%. Or should the person in question not have bought a laboratory device for X hundred euros.

author: Aldo22
author_rank: Super Contributor
timestamp: June 25, 2025, 04:21:45 pm
content: Thanks jebem!Yes, I was just wondering whether I could get by with “home remedies” in these border ranges, where I would also be satisfied with 2-3%, without buying reference resistors.I mean, just in case the values differ a lot after the update to 1.0.8.I see that you haven't done the update yet either?By “home remedy” I simply mean what I have here.The resistor board should actually be sufficient for 10M, we don't have that many counts.For 0.1Ω I have a resistor (I don't know the details) and for 0.01Ω I have a wire (see photos attached).This is certainly not perfect, but is it good enough in case it becomes necessary?Do we actually have to calibrate separately for the 4-wire Kelvin clips?At what frequency? Does it do this automatically?

author: mawyatt
author_rank: Super Contributor
timestamp: June 25, 2025, 04:37:25 pm
content: Josh created a nice PCB with various SMD RLC components that can be probed with Kelvin Clips, might be worth a look.Best

author: chukin
author_rank: Contributor
timestamp: June 25, 2025, 07:27:50 pm
content: Quote from: Aldo22 on June 19, 2025, 08:48:05 amSali Aldo, it's nice to share the self-flagellation.... I looked up your seller and bought the same one for even cheaper than you did. I don't blame just you...it was defpom too - his video made it irresistable for the price.Let's see if it gets to Switzerland as quickly as your's did.CheersPeter

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 25, 2025, 09:19:32 pm
content: If anybody wants my V5 LCR Test PCB fully populated (and tested), send me a DQ02, and I'll send the test PCB to you. 😉 I'm not gonna buy one of these while there's still stupid tariffs on it.

author: BillyO
author_rank: Super Contributor
timestamp: June 25, 2025, 09:26:16 pm
content: Quote from: KungFuJosh on June 25, 2025, 09:19:32 pmJust get them to send it to you and claim it's "cellular communications equipment" which is exempt from the tariffs. Why? Because of Trump Mobile, of course. Which, despite the the wonderfully honest and darling Trump family's claims that Trump Mobile is "all American", is having their trash phones made in China. Just some fun facts. You get to pay tariffs, they don't. Nice.

author: Aldo22
author_rank: Super Contributor
timestamp: June 25, 2025, 10:20:48 pm
content: I have updated to 1.0.8.The measured values are still largely OK, even without calibration.But REL no longer works. This worked with 1.0.7, even if it was a bit unclear.

author: Alphataurus
author_rank: Contributor
timestamp: June 25, 2025, 10:25:39 pm
content: About calibration resistors, I have ordered some EE type resistors from this store:https://www.aliexpress.com/item/1005005975520034.htmlI haven't received them yet, I ordered them on June 2, but I didn't check the default shipping method and they have an arrival date of July 21. Watch for this if anyone orders them, because for little more cost they can arrive much sooner.Other resistors I have already received are these:https://www.aliexpress.com/item/1005007708884463.htmlThey include a label with the measurement made by the seller, the ones I have received using Keithley DMM7510 or Hioki 3541.They seem to be of good quality, the results I have measured match but I don't have equipment calibrated for 5 digit measurements, internally they have SMD resistors.They are expensive, but I have bought them with coin offers up to 60-70% IIRC, I guess if you are patient these offers will come back.

author: mawyatt
author_rank: Super Contributor
timestamp: June 26, 2025, 12:24:06 am
content: If you want to DIY Precision Resistors, here's a link with what we did. We use Vishay Resistors which are known to be quality components. Interesting that the Bench DMMs Banana Jacks are much higher temperature than ambient.https://www.eevblog.com/forum/projects/cheap-precision-resistor-mounting-scheme-with-built-in-thermistor/msg5841147/#msg5841147Best

author: Aldo22
author_rank: Super Contributor
timestamp: June 26, 2025, 05:33:43 pm
content: I have now tried it out a bit.It's really very cheap for what you get, but to be honest I find the ZT-MD1 more practical and it seems somehow more mature.The ZT-DQ02 has (too) many options. You often don't know whether you've set something wrong again or whether you've stumbled across a new bug.Often it is probably a bug.The many connection options don't make it any easier either. Do you always have to recalibrate them (open/close)?To be honest, I trust the little ZT-MD1 more at the moment. It gives me more confidence and is easier to use.Maybe one day I'll learn how to use the DQ02.

author: jebem
author_rank: Regular Contributor
timestamp: June 26, 2025, 06:49:06 pm
content: Quote from: Aldo22 on June 26, 2025, 05:33:43 pmI am ok with my unit but I have just received it a few days ago, so time is needed to evaluate it.I did not update it to 1.08 as I do not feel the need to do it now.And never tried to calibrate it because I do not have precision resistors (the ones that cost above 20 EUR each).Concerning calibration, the user guide seems to be detailed enough to be followed.That is why I ordered those low cost (<3EUR each) 0.1% resistors in the exact values listed on the user guide.I agree with you that the ZT-MD1 is very practical and give easy readings. It is good enough for the job when we need to measure in-circuit components.

author: coromonadalix
author_rank: Super Contributor
timestamp: June 26, 2025, 07:29:36 pm
content: no luck from me ordering theses resistors Ali complains about too many specials reductions prices / too many .. and fail pffffffi wanted the 0.01, 0.1, 1, 10, 100, 1k, 10k, 100k, 1 meg ones ...

author: mawyatt
author_rank: Super Contributor
timestamp: June 26, 2025, 07:37:10 pm
content: Mouser has a good selection of precision (<= 0.1%) leaded and SMD resistors.Best

author: UnijunctionTransistor
author_rank: Frequent Contributor
timestamp: June 26, 2025, 07:51:28 pm
content: Quote from: tszaboo on April 08, 2025, 07:48:53 pmResistance is futile.Capacitance and inductance? That is another story.

author: Aldo22
author_rank: Super Contributor
timestamp: June 26, 2025, 09:34:14 pm
content: Quote from: jebem on June 26, 2025, 06:49:06 pmI am back to version 1.0.7. "REL" does not work on 1.0.8. The downgrade was problem-free.I did a testherewith a few capacitors using the ZT-MD1.That all made sense with the dissipation factor "D", see the lower values at 7,8,9.If I do the same test with the same capacitors with the DQ02, I don't get this difference in D.Unfortunately the DQ02 does not have a logfile function like the MD1, so I had to type in the values manually.Which device should I believe now? The MD1 or the DQ02? Or have I made a mistake? Both at 1kHz and 0.6V.Code:No. Val D1 9.978nF 0.00352 21.035nF 0.00383 34.550nF 0.00344 38.709nF 0.00415 47.366nF 0.00376 99.03nF 0.00317 150.09nF 0.00348 213.4nF 0.00329 356.00nF 0.003310 485.89nF 0.0037

author: GigaJoe
author_rank: Frequent Contributor
timestamp: June 26, 2025, 10:58:18 pm
content: Quote from: coromonadalix on June 26, 2025, 07:29:36 pmactually you need '0' - that would be special 4W short , and 10M ..and if you have the way to measure 10m more less precisely ( i believe you can) , it better to make it yourself with 0.1 ohm in 10 parallel SMD , you can find relatively cheap.keep in mind -- in overall it need just transfer value. Means: construct 4W 0.01R resistance out of 10 0.1R + multiturn potentiometer , connect to DUT with FW1.07adjust to precise readings of 0.01R .. update to 1.08 , calibrate back using the same 0.01R ...done ... just prepare as much value as you need before FW updates .... in that technique you basically do not add any error ... if you have more precise equipment .. even better

author: indman
author_rank: Super Contributor
timestamp: June 27, 2025, 07:54:40 am
content: Quote from: Aldo22 on June 26, 2025, 09:34:14 pmYou can't trust any of your counters yet!Until you compare them with more professional devices!If with measuring the main parameters of LCR these cheap counters cope quite successfully, then with the measurement of no less important secondary parameters Z, D, Q, Θ, X, Rs/Rp they have sufficiently serious problems at different frequencies.The reason for this was explained in great detail by a respectedmawyatthttps://www.eevblog.com/forum/testgear/new-lcr-meters-zoyi-zt-dq01-and-zoyi-zt-dq02-(march-2025)/msg5913394/#msg5913394

author: Aldo22
author_rank: Super Contributor
timestamp: June 27, 2025, 09:17:56 am
content: Quote from: indman on June 27, 2025, 07:54:40 amYes, unfortunately it looks like that.Then I'll probably never know.The MD1 values look a bit more plausible to me because they make a difference. With the DQ02, all the D values are about the same.But maybe that's closer to the truth, or maybe they're both wrong. ...Thank you.

author: svetlov
author_rank: Regular Contributor
timestamp: June 27, 2025, 10:04:14 am
content: pay attention to this device NJ101S, which came out about 5 years agofor itsprice it has impressive accuracy- the author, using the links below, managed to get an error of ±0.2 fF on reference capacitors on this device, these are femtofarads! the measurement frequency, for example, for the NJ101S model is up to 300 kilohertz!https://ampnuts.ru/lcr-nj100s/https://ampnuts.ru/start/https://www.eevblog.com/forum/testgear/rcl-meters-of-type-nj100s-nj200s-nj300s/https://forum.nickbel.com/index.php?topic=25.0link to the device read reviews but it looks like the kit does not include 4 wire measuring leadshttps://aliexpress.ru/item/1005001703481474.html?sku_id=12000017220315668&spm=a2g2w.productlist.search_results.5.3e0444a124cbfA

author: jebem
author_rank: Regular Contributor
timestamp: June 27, 2025, 01:03:55 pm
content: Quote from: Aldo22 on June 26, 2025, 09:34:14 pmGlad that you managed to rollback to V1.07 without issues.Hopefully ZOYI will read about the V1.08 issues here and elsewhere and release a fix soon.I feel the same way about these "low cost" meters.I got two LCR tweezers, one FNIRSI LCR-ST1 and one LCR DQ02 MD1, not to mention a few Multi-testers like the FNIRSI LCR-P1 in addition to the ZT-DQ02 and my older Proster BM4070 LCR.None of them agree to the last one or two digits on any measurement, but this is expected.They are very useful for troubleshooting and regular design projects. The difference in readings are not that huge and can simply be ignored, or else take at least three different LCR models to do measurements, then chose the two closest readings and discard the third one.They are not precision instruments despite having so many display digits.To achieve trusty high precision, several thousand Euros is required.None of the low cost ones are equipped with proper temperature compensation and stabilization systems, the selected components are hardly considered high precision ones.Additionally, different algorithms will transform the input data into different primary and secondary readings.

author: coromonadalix
author_rank: Super Contributor
timestamp: June 27, 2025, 01:45:08 pm
content: always the same .... resolution versus precision ...exactly my thoughts, useful instruments, not for absolute precisioni'll cobble together a few big caps over 10,000 uf to see higher than 20,000uf limits, seen on many hand held lcr's, i run occasionally on 25,000 uf / 400v caps on huge laser psu ...and eventually do some compare with an Sencore lc102 ...i just need to finish calibrating it / checking it's specs, around 25-26 trimpots loll, need some caps and coils to finish it as per calibration documents

author: mawyatt
author_rank: Super Contributor
timestamp: June 27, 2025, 02:36:59 pm
content: One thing to consider when attempting quality, repeatable LCR measurements is the DUT Voltage and Current. Some of the better bench type meters display the DUT measured scaled magnitude voltage and current. For good results keep these magnitudes within reasonable measurement ranges. When we are making measurements with our two bench LCR meters (TH2830 and IM3536) these values are often viewed to assure the meters are within their "Sweet Spot" for best results.Complex LCR Meter DUT graphs usually are available which reflect these "Sweep Spot" DUT ranges and should be consulted when desiring high quality, repeatable measurements.Another important consideration when making quality measurements is the meter external cables and fixtures. Many core bench meters can measure down to fractional picofarads and milliohms, however the cables and fixtures can and will corrupt these lower levels and create additional measurement uncertainty. Attention to Open and Short Calibration at every test frequency after proper instrument/fixture/cable warmup and rigid mechanical/electrical/ambient environments will pay dividends, but often neglectedA good example of is the use of a "Guard" shield plate when making Kelvin Clip measurements, where measurement Kelvin Clips are positioned and taped to hold above a Guard Plate connected to the LCR Meter Guard terminals. This is highlighted in the Hioki Bench LCR Meter Manuals and our direct experience using a PCBite magnetic plate as the Guard Plate has proved worthwhile.Best

author: Aldo22
author_rank: Super Contributor
timestamp: June 27, 2025, 02:38:32 pm
content: The question I'm asking myself is whether it's worth buying the DQ02 if you already have an MD1.Don't get me wrong, the DQ02 looks great and is very sturdy. The screen is excellent and the price with all the accessories is really very cheap. It also has the battery tester.I'm just wondering if it really gives me more information about my DUT than the $20 MD1.I'm not so sure and I'm a bit disappointed. Somehow the MD1 seems like the better buy.And I really miss the log file of the MD1. Apparently there is something with SCPI with the DQ02, but that must be a secret.

author: RAPo
author_rank: Super Contributor
timestamp: June 27, 2025, 03:02:06 pm
content: I'm also considering a rollback to 1.7. Do you have the firmware file (or a link to it)?Quote from: Aldo22 on June 26, 2025, 09:34:14 pm

author: Aldo22
author_rank: Super Contributor
timestamp: June 27, 2025, 03:22:43 pm
content: Quote from: RAPo on June 27, 2025, 03:02:06 pm1.0.7 is still the latest official version on zotektools.comhttps://drive.google.com/file/d/1bnWXEzwpgmzZDq96qvKve1oouGaWsEZa/viewhttps://zotektools.com/products/zoyi-zt-dq02/

author: coromonadalix
author_rank: Super Contributor
timestamp: June 27, 2025, 03:30:41 pm
content: check earlier threads here, i posted all of them too .... and others members as well ...i love the way to downgrade or upgrade them, in windows, they appears as a connected drive, dump the FW in it, and reboot

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 27, 2025, 05:29:58 pm
content: Quote from: Aldo22 on June 27, 2025, 02:38:32 pmThe simple answer is no, but if you want another toy, then yes. There's no value in owning a 2nd LCR of similar low quality/accuracy/believability. If you want sanity checks, you need something of higher quality with a trustworthy calibration certificate.Don't get me wrong, I love getting the toys too. I want a DQ02 to test against higher quality meters and see how it performs. But the stupid tariffs are denying that inevitably brief entertainment.

author: Aldo22
author_rank: Super Contributor
timestamp: June 27, 2025, 05:44:52 pm
content: Quote from: coromonadalix on June 27, 2025, 03:30:41 pmExactly, the MD1 works the same way.Can anyone confirm that a factory reset resets all calibration data to the original settings?Can I experiment with the calibration and always go back?

author: Aldo22
author_rank: Super Contributor
timestamp: June 27, 2025, 06:16:07 pm
content: Is there any information about the SCPI commands of this device?I have briefly tested whether I can address it and it works.Code:import pyvisarm = pyvisa.ResourceManager()#print(rm.list_resources())my_instrument = rm.open_resource('ASRL/dev/ttyACM0::INSTR')print(my_instrument.query('*IDN?'))Returns:Code:ZOYI,ZT-DQ02,9D85F8BF,V1.0.7EDIT: I tried something with FETCh? and nothing worked with 1.0.7.In fact, it seems to be a work in progress, like so many things here.I only found such a string in the binary code of 1.0.8.That is probably why it is not yet documented.Hopefully it will all work out.Code:0001:0650 | 00 00 00 00 00 00 00 00 46 45 54 43 68 3F 00 00 | ........FETCh?..0001:0660 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:0670 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:0680 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:0690 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:06A0 | 7D 2E 01 08 00 00 00 00 00 00 00 00 00 00 00 00 | }...............0001:06B0 | 46 52 45 51 75 65 6E 63 79 3F 00 00 00 00 00 00 | FREQuency?......0001:06C0 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:06D0 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:06E0 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:06F0 | 00 00 00 00 00 00 00 00 01 31 01 08 00 00 00 00 | .........1......0001:0700 | 00 00 00 00 00 00 00 00 56 4F 4C 54 61 67 65 3F | ........VOLTage?0001:0710 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:0720 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:0730 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:0740 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:0750 | 99 31 01 08 00 00 00 00 00 00 00 00 00 00 00 00 | .1..............0001:0760 | 42 49 41 53 00 00 00 00 00 00 00 00 00 00 00 00 | BIAS............0001:0770 | 00 00 56 4F 4C 54 61 67 65 3F 00 00 00 00 00 00 | ..VOLTage?......0001:0780 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:0790 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:07A0 | 00 00 00 00 00 00 00 00 69 2D 01 08 00 00 00 00 | ........i-......0001:07B0 | 00 00 00 00 00 00 00 00 41 50 45 52 74 75 72 65 | ........APERture0001:07C0 | 3F 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ?...............0001:07D0 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:07E0 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:07F0 | 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 | ................0001:0800 | 25 31 01 08 00 00 00 00 00 00 00 00 00 00 00 00 | %1..............0001:0810 | 46 55 4E 43 74 69 6F 6E 00 00 00 00 00 00 00 00 | FUNCtion........0001:0820 | 00 00 49 4D 50 65 64 61 6E 63 65 00 00 00 00 00 | ..IMPedance.....0001:0830 | 00 00 00 00 4D 41 49 4E 3F 00 00 00 00 00 00 00 | ....MAIN?.......

author: KungFuJosh
author_rank: Super Contributor
timestamp: June 27, 2025, 07:58:37 pm
content: Have you tried FREQ? and VOLT? yet?

author: Aldo22
author_rank: Super Contributor
timestamp: June 27, 2025, 08:02:10 pm
content: Quote from: KungFuJosh on June 27, 2025, 07:58:37 pmNo, I downgraded back to 1.0.7 yesterday and none of this works with this version.With 1.0.8 it probably does, but I won't try that today.

author: Aldo22
author_rank: Super Contributor
timestamp: June 27, 2025, 08:31:33 pm
content: OK, I had to try that out after all.So FETCh? works with (and only with) 1.0.8 and returns something like this for a 1k Resistor, 600mV, 1kHzCode:'1.0005e3', '-1.3828', 'R', 'R', 'X', 'AUTO', 'SER', 'SLOW', 'AUTO', '1000', '600', '0', '0', 'R', '1.0000e3', '5.0', '0'I couldn't get VOLT and FREQ to work.It seems promising, but I think it's not finished yet.It's probably better to wait for the documentation.

author: ander7
author_rank: Contributor
timestamp: June 29, 2025, 07:25:39 am
content: SCPI commands extracted from firmware v1.0.7CommandExample output*CLS*ESE*ESE?*ESR?*IDN?ZOYI,ZT-DQ02,903D9C87,V1.0.7*OPC*OPC?*RST*SRE*SRE?*STB?*WAI*TST?:STATus:OPERation?0:SYST:ERR?0,"No error":SYSTem:ERRor:NEXT?0,"No error":SYSTem:ERRor:ALL?0,"No error":SYSTem:ERRor:CLEAR:SYSTem:ERRor:COUNt?0:SYSTem:ERRor:CODE?0:SYSTem:ERRor:CODE:NEXT?0:SYSTem:ERRor:CODE:ALL?:SYSTem:VERSion?1999.0:STATus:OPERation:EVENt?0:STATus:OPERation:CONDition?0:STATUS:OPERation:ENABle?65535:STATUS:OPERation:ENABle PARAM:STATus:QUEStionable?0:STATus:QUEStionable:EVENt?0:STATus:QUEStionable:CONDition?0:STATus:QUEStionable:ENABle?65535:STATus:QUEStionable:ENABle PARAM:STATus:PRESetBut I don't see any commands to fetch values in this version.

author: Aldo22
author_rank: Super Contributor
timestamp: June 29, 2025, 08:08:04 am
content: Quote from: ander7 on June 29, 2025, 07:25:39 amNo, only in 1.0.8. That's what I wrote above.

author: ander7
author_rank: Contributor
timestamp: June 29, 2025, 08:09:42 am
content: Quote from: Aldo22 on June 29, 2025, 08:08:04 amWhere did you get 1.0.8 firmware?

author: Aldo22
author_rank: Super Contributor
timestamp: June 29, 2025, 08:12:14 am
content: Quote from: LeonR on June 16, 2025, 08:53:40 pmTrue, I've just noticed that too. It seems to be the same with all stores.For me, it was the included Kelvin clips that made me press the order button.I also wonder why they include standard DMM test leads and not thesetweezers, which are much more useful for SMD and often for in-circuit measurements.They are certainly not more expensive.

author: Aldo22
author_rank: Super Contributor
timestamp: June 29, 2025, 08:13:43 am
content: Quote from: ander7 on June 29, 2025, 08:09:42 amhttps://www.eevblog.com/forum/testgear/new-lcr-meters-zoyi-zt-dq01-and-zoyi-zt-dq02-(march-2025)/msg5929764/#msg5929764But beware, there are new bugs, I'm back to 1.0.7.

author: gameru
author_rank: Contributor
timestamp: July 02, 2025, 03:23:14 pm
content: Hi everyone,Did you see this video? →At around minute 11, the reviewer tries to measure a resistor, and the value shown by the Zoyi DQ02 is almost twice the real value.Have you encountered this issue as well? Is it normal for this LCR meter to show such a big error when measuring resistance?The guy in the video used a 0.22 Ohm 3-leg non-inductive resistor and compared the measurement with a Vici VC480C+. The DQ02 displayed a value that was about twice as high.I’ve also ordered the Zoyi ZT-DQ02, but it hasn’t arrived yet.

author: coromonadalix
author_rank: Super Contributor
timestamp: July 02, 2025, 03:54:07 pm
content: and the FW version is ? unless i did not see that in the video ?that's an important one to list when you create video(s)

author: Aldo22
author_rank: Super Contributor
timestamp: July 02, 2025, 04:30:34 pm
content: Quote from: gameru on July 02, 2025, 03:23:14 pmYoutubers often do strange things.I don't see the problem with my device (FW 1.0.7).In the attached photo 100mΩ.

author: gameru
author_rank: Contributor
timestamp: July 02, 2025, 05:30:14 pm
content: Hi! I didn’t create the video, I just watched it and shared my thoughts based on it. But yes, I agree – the firmware version is definitely worth mentioning!

author: Alphataurus
author_rank: Contributor
timestamp: July 02, 2025, 05:40:21 pm
content: On mine, FW version 1.0.7, there is another bug there.The tests are done using 1% resistance, with the BAT connector on Zoyi I get 99.45 mOhm, with YR1035+ 99.9 mOhm, and with the YR2050 99.88 mOhm.Inserting the resistor in the rectangular connectors of the Zoyi, the results are in milliohms at levels 0.1V / 0.3V / 0.6V, the last digits sometimes are not stable and can fluctuate up to about +/- 1 mOhm:100 Hz: 101 / 101 / 101120 Hz: 101 / 101 / 1011000 Hz: 101 /46/4610 KHz: 102 / 102 / 102100 KHz: 110 / 124 / 105There are also bugs in the manual ranges, sometimes I get measurements of 150 or even 170 mOhm in the lower 100 Ohm range, and good ones in the 100 KOhm range, sometimes they are solved by changing the range and selecting it again, and sometimes not.It is true that for more precision in such low resistances the higher connector should be used, but these errors are unacceptable, I don't have time to test higher resistances, but I wouldn't be surprised if they also happen.

author: Alphataurus
author_rank: Contributor
timestamp: July 02, 2025, 06:28:15 pm
content: Quote from: coromonadalix on July 02, 2025, 03:54:07 pmHe is using FW 1.0.7, minute 7:05

author: Aldo22
author_rank: Super Contributor
timestamp: July 02, 2025, 07:09:54 pm
content: Quote from: Alphataurus on July 02, 2025, 05:40:21 pmI think there is something wrong with the “REL” function.Try a factory reset, no “REL” and measure again. That helped in my case.

author: papabol_24
author_rank: Contributor
timestamp: July 02, 2025, 07:29:01 pm
content: Quote from: gameru on July 02, 2025, 03:23:14 pmI think its because he did a resistor (1M) calibration without actually connecting a 1M resistor.

author: Alphataurus
author_rank: Contributor
timestamp: July 02, 2025, 07:50:51 pm
content: Quote from: Aldo22 on July 02, 2025, 07:09:54 pmBravo! this solves the readings at 1 kHz in auto mode, at 100 kHz I still sometimes have the somewhat inconsistent 110 / 124 / 105 or similar, although this is not a big problem because it should not be measured at this frequency.Just as you said, it seems that the problem is in the REL button, I never tried to use it, but I surely pressed it in the past sometime. It seems to save some configuration for the different frequencies, levels and ranges. Not bad, but it doesn't indicate anywhere when a relative measurement is being made.With manual ranges, I still sometimes get measurements of 170-180 milliohms at 100 Hz, 0.6V, 100 Ohm range, and good ones at 100 kOhm range. It looks like the bug is there, and it is the one that happens to the guy of the video.

author: GigaJoe
author_rank: Frequent Contributor
timestamp: July 02, 2025, 09:12:32 pm
content: 1.0.7: another bug , manual range 100 Ohm1K or others - "OL"and this range "100 ohm" , do displayed regardless R , C ,or L ..."REL" option are pure devil.. first: not precisely define REL .. ; if you press and hold couple times it finally shows '0' , then it save the result , so power ON/OFF recall last REL status ....for 1.0.8 or let say BETA 1.0.8 , REL disabled but still exist for C and L ... guess they may fix behavior for resistance

author: Aldo22
author_rank: Super Contributor
timestamp: July 03, 2025, 09:57:10 am
content: "REL" is a really strange, cryptic thing. Somehow it only seems to work with 0.6V.There is absolutely no indication that it is working. You can't undo it either (except with factory reset), although it interferes with subsequent measurements.In 1.0.8 it seems to have been disabled (or not?). But that's not good either, because you need it for 2-wire measurements (tweezer, test leads).The ZT-DQ02 is really the most half-baked device I've ever had from Zotek. The MD1 is more reliable.

author: Nospa
author_rank: Contributor
timestamp: July 03, 2025, 10:57:44 pm
content: I got a DQ02 today and checked the output signal on the scope...Question: The 'Level' setting appears to be RMS and not Peak-to-Peak. Is this expected?My expectation would have been 'Level' to be the Peak-to-Peak. E.g. setting 0.1V to avoid activating any P-N junctions when measuring in circuit.Level 0.1VLevel 0.3VLevel 0.6VLevel 0.1V + Bias 0.5VLevel 0.3V + Bias 0.5V

author: Nospa
author_rank: Contributor
timestamp: July 04, 2025, 03:07:11 am
content: Quote from: GigaJoe on July 02, 2025, 09:12:32 pmI think 'range' does NOT refer to the measurement range (like on a DMM).The 'range' setting could allow to manually select the internal range resistor value that is used during measurement. So it doesn't matter if you are measuring R, C or L - it will always be an Ohms setting.This video helps getting a grip on how these things work:The range resistor is explained too...

author: GigaJoe
author_rank: Frequent Contributor
timestamp: July 05, 2025, 01:58:15 am
content: great , thanks, i'm kinda forgot about ..Manual says "15 Range | Displays the set resistance test range "

author: AnaMary
author_rank: Newbie
timestamp: July 05, 2025, 03:17:27 pm
content: Hola, de donde descargaste la versión 1.0.8? En la pagina de Zoyi solo te deja descargar la 1.0.7, agradecería me indiques de donde descargarla o me la envíes, un saludo.Traducción Google:Hi, where did you download firmware 1.0.8? Zoyi website only lets you download firmware 1.0.7. I'd appreciate it if you could tell me where to download it or send it to me. Best regards.

author: Nospa
author_rank: Contributor
timestamp: July 05, 2025, 05:47:12 pm
content: Apparently the new Zoyi homepage doesn't list all firmware versions.The old hompage does:http://www.szzotek.com/h-col-159.htmlI'm attaching the 1.0.8 version downloaded from the old site along with the google-translated release notes (originally a picture of chinese text inside the original zip).The fw file is the .bin.txt file - can't upload w/o messing with the file extension.Also apparently another 1.0.8 file exits that was posted on a chinese forum - super messy situation...EDIT: This is for the DQ2 obviously...

author: TvNieuw
author_rank: Newbie
timestamp: July 09, 2025, 01:14:52 pm
content: Hi, Update from the Netherlands.Quite pleased with my ZT-DQ02 FW 1.08.However I did find some quirks.When calibrating the Battery testleads  and [-60V] the calibration would always fail with FW 1.08.To investigate I downgraded to FW 1.07. Calibration for  and all Voltages were GO!After upgrading again to FW 1.08 and trying to calibrate the battery testleads,  and [-60 V] would fail time and time again.Why you'd wonder? Well after some thinking I had an idea to isolate the Kelvin clips. When shorting Hcur and Lcur only the  calibration went okay.After the  was done the Calibration of [-60V] also worked.After generating and calibrating positive and negative 60V 10V and 1V it seems to be much more precise in measuring Voltage.I'm still not convinced the Battery Ohms measurement is accurate.

author: GigaJoe
author_rank: Frequent Contributor
timestamp: July 09, 2025, 10:51:19 pm
content: so i got one of 18650 , measure voltage load \ no load . got 0.24 ohm . then try a difference more load \ less load, same resistance.DQ02 - shows 0.094 ohm ; some charger 0.055 ohm ( but i guess it so so) ...I'm measure \ calculating over V and A using load incorrectly , or still incorrect DQ02 measurement ? I do not calibrate it at all ... (waiting resistors )

author: Alphataurus
author_rank: Contributor
timestamp: July 10, 2025, 07:28:37 pm
content: Quote from: GigaJoe on July 09, 2025, 10:51:19 pmI think the DQ02 uses the AC method to measure the internal resistance of the battery, when I received it I compared the results with a yr1035+ and IIRC they were not exactly the same but similar.I think I read something about it on this forum but can't find it, maybe this might help:https://lygte-info.dk/info/Internal%20impedance%20UK.htmlhttps://lygte-info.dk/review/InternalResistanceMeterYR1035%20UK.html

author: Propretor
author_rank: Regular Contributor
timestamp: July 11, 2025, 08:18:56 pm
content: Quote from: dmitrkov on June 20, 2025, 01:15:16 pmI bought the same resistors. Everyone writes that they are supposedly non-inductive. Calibration with 10MΩ resistor is not possible. That is, the calibration ends with a green backlight background, but the readings after calibration with it jump from 8 to 16MΩ on firmware 1.0.8. I didn't check with other firmware. I don't believe you were able to calibrate with this resistor.

author: BillyO
author_rank: Super Contributor
timestamp: July 11, 2025, 09:27:54 pm
content: Quote from: Propretor on July 11, 2025, 08:18:56 pmWhat frequency are you using to do the measurement?

author: Nospa
author_rank: Contributor
timestamp: July 12, 2025, 12:50:02 am
content: I've been testing theRangesetting some more:For DUTs with 'low' resistance values the test signal gets cut off depending on theRangesetting- 1k and 10k show exactly the same cut off signal- AUTO, 100R, 100k show the proper test signal (yes, 100K behaves exactly the same as 100R)- the cut off happens for 0.3V and 0.6Vlevelsettings - the lower the level, the lower the required R_DUT to distort the signalThe screenshot shows- the proper sine signal observed atRange=AUTO, 100R, 100k (channel RefA)- the cutoff signal observed atRange=1k and 10k (channel C1, 20mV offset so wave forms don't overlap)Settings are- Freq=100Hz, Level=0.6V, Bias=0.- Measurement mode doesn't have an influence except ECAP (biased) and Battery Test mode of course- Freq setting has no influence either regarding the 'distortion shape' and amplitude- DUT is an ordinary 100 Ohm resistorThis is all on fw v1.0.7Edit: Verified on v1.0.8 - exactly the same behavior.Analog gurus please chime in - what are we looking at here?

author: Nospa
author_rank: Contributor
timestamp: July 12, 2025, 12:10:07 pm
content: More tests done, more oddities found:Changing theRangesetting while the DUT (100R resistor again) is connected leads to completely different readouts than changingRangewhile DUT is disconnected.SwitchingRangefrom 100R to 1k while DUT (100R resistor) is...... connected:R=108.17 --> R=135.16... disconnected:R=108.20 -->R=560.12(!!!!!!!!!)Tests done on fw V1.0.7.This device is so buggy, it's hard to trust any reading without knowing the expected values in advance.

author: ander7
author_rank: Contributor
timestamp: July 12, 2025, 12:59:05 pm
content: For those who are missing battery holder for DQ02 - you can use accessories from YR1035+ or build you own (required connector is xs10-4p/female)Battery test socket pinout:1: positive2: positive3: negative4: negative

author: ander7
author_rank: Contributor
timestamp: July 12, 2025, 01:10:24 pm
content: Quote from: Nospa on July 12, 2025, 12:10:07 pmI have exactly the same behavior on my DQ02 (firmware is 1.0.7)

author: ander7
author_rank: Contributor
timestamp: July 12, 2025, 01:26:33 pm
content: I think this issue is a result of wrong interpretation of "Range" function of this device since it can measure 10k resistance on 100 Ohm range.

author: BillyO
author_rank: Super Contributor
timestamp: July 12, 2025, 02:06:11 pm
content: What frequency are you using to test these resistors and what kind of resistors are they? First, don't just assume you resistors are free from inductance. Most are not. Test resistors at the lowest possible frequency you device has to eliminate the effect of inductance.Also, if you are having problems, imagined or not, with V1.0.7, update to V1.0.8The one I have, on V1.0.8, has no issue whatsoever measuring a 100Ω resistor on any range:Code:Range Value100Ω 100.15Ω1KΩ 100.18Ω10KΩ 100.16Ω100KΩ 100.16ΩAuto 100.15Ω

author: Aldo22
author_rank: Super Contributor
timestamp: July 12, 2025, 02:27:44 pm
content: Quote from: Nospa on July 12, 2025, 12:10:07 pmThe problem is that this device has too many options for the layman and probably also for the developer.But at this price, it's not a professional tool, so it's aimed at hobbyists/laymen.You really don't know if you just don't understand how it works or if you've just stumbled across a bug.You get the feeling that you can have virtually any measurement result from the device, depending on how you set it up.That alone makes it difficult to recommend.Then there are different FW versions that fix some problems and create other problems.I hope that with further FW updates this will all develop in a good direction, but at the moment I would rather recommend the ZT-MD1, if only because there is less that can go wrong.

author: Propretor
author_rank: Regular Contributor
timestamp: July 12, 2025, 03:16:45 pm
content: Quote from: BillyO on July 11, 2025, 09:27:54 pm100Hz to minimize the inductive component of impedance.

author: Nospa
author_rank: Contributor
timestamp: July 12, 2025, 03:32:40 pm
content: Quote from: Aldo22 on July 12, 2025, 02:27:44 pmSorry to disagree - just look at the facts I listed in the previous posts - from signal distortion to order of setting a range before or after connecting a DUT affecting the reading by factor 5 (!!!).This is not me being overwhelmed by 'options' and settings...Currently my goal is just determining what the Range setting actually is. Resistor in series with DUT on the cur line pair? How does it lead to the strange test signal distortion? Etc etc...

author: BillyO
author_rank: Super Contributor
timestamp: July 12, 2025, 03:47:55 pm
content: Quote from: Nospa on July 12, 2025, 03:32:40 pmNo, he's right. All I see here is a bunch of folks, the first thing they do is get this new toy, then destroying the factory calibration with resistors of unknown quality. Why? Oh good lord, why?Then I read that someone is changing the range without the DUT attached, as if this is a use case??!?! In fact, did you read the manual? (What a concept!!)Page 10Range SettingQuoteNothing there about removing the DUT, change setting, re-attach the DUT. They specifically tell you how to use the range, but you want to re-invent how you are supposed to use it. Just use it the way they tell you to use it. As you may have seen in my post above, I got consistent and accurate results doing it correctly.But maybe you are the kind of guy that uses a wrench as a hammer.

author: Nospa
author_rank: Contributor
timestamp: July 12, 2025, 04:29:36 pm
content: Quote from: BillyO on July 12, 2025, 03:47:55 pmThanks for the constructive reply!Of course I didn't read the manual, instead I whipped out the scope and tried to figure out what all those fancy buttons do...!So, as you are so fluent in that manual-reading-thing:Where does it say tonever ever disconnect one DUT after having found a range (as per instructions) and then connect a similar DUT (e.g. to compare)because it will f up the 2nd and following readings by a random factor of e.g. x5?Also I don't use wrenches as hammers - that's what vernier calipers are for!

author: BillyO
author_rank: Super Contributor
timestamp: July 12, 2025, 04:47:00 pm
content: Ya, right.The way I read it is - use auto mode. (And I don't mean auto function, but that will work in most cases)Otherwise, if you that does not work, follow the process defined in the manual for employing the ranges. This what the meter itself does. It tries 100Ω first, then adjusts the range from there. Like all auto ranging every where in the world.This is an automatic bridge. It's not a DMM. It uses a completely different method to measure resistance. Whatever the precise algorithm it uses is, and this is hinted to in the process outlined in procedure on page 10, my guess is it uses the 100Ω range to set a baseline balance, then refines it from there by going up in range.I have tried this a dozen times now with different value resistors. Start at 100Ω. work your way up. Consistent and accurate results EVERY. SINGLE. TIME.That said, doing that has never provided a better result than just using auto mode in the R function.Aldo22 had it just right. They put too much functionality into this entry level device. People are fiddling with all the bells a whistles and getting tripped up.

author: Alphataurus
author_rank: Contributor
timestamp: July 12, 2025, 08:28:46 pm
content: There is a new review from a few days ago by Tony Albus comparing DQ01 and DQ02, some component measurements using 1.0.8, and teardown.

author: Aldo22
author_rank: Super Contributor
timestamp: July 13, 2025, 08:14:57 am
content: Quote from: Alphataurus on July 12, 2025, 08:28:46 pmNice, but really not much new.I would have expected him to shed some light on the secondary parameters and play with the settings.The measured values aren't really interesting either.100Ω - 100kΩ, my DMM is good enough and easier for that. You don't need a Kelvin clip for that either.mΩ or MΩ would have been more interesting. The same for L and C values.What do you think?

author: Alphataurus
author_rank: Contributor
timestamp: July 13, 2025, 12:20:08 pm
content: Quote from: Aldo22 on July 13, 2025, 08:14:57 amI think the same as you, few measurements of components. It would be interesting more measurements because it seems he has good standards, even compare these measurements with the rest of portable LCR he has, i.e. ET432, DE5000 and Hantek 1833c. But this is a lot of work, maybe he will cheer up in the future.The most interesting thing could be that it seems that after the upgrade from 1.0.7 to 1.0.8 a total recalibration of the equipment is not necessary because the measurements seem to be correct, but he did not take measurements before upgrading, I think I read here that recalibration was necessary after upgrading. In any case, knowing that you can go back to the previous version, maybe in the future I can compare measurements with version 1.0.7 and 1.0.8 without recalibration, right now I don't have much time.

author: BillyO
author_rank: Super Contributor
timestamp: July 13, 2025, 02:48:45 pm
content: Quote from: Alphataurus on July 13, 2025, 12:20:08 pmOf course it isn't. Calibration is hardware dependent - to correct for variances in components from device to device. They all use the same code, so that cannot be the reason that calibration is required.

author: andre3d
author_rank: Contributor
timestamp: July 13, 2025, 03:30:29 pm
content: Quote from: BillyO on July 13, 2025, 02:48:45 pmYou are not taking into account the calibration error in the previous code. After correcting the calibration in the new code, it is necessary to calibrate again.

author: BillyO
author_rank: Super Contributor
timestamp: July 13, 2025, 03:33:07 pm
content: Quote from: andre3d on July 13, 2025, 03:30:29 pmWhat is the evidence for this .. calibration error?

author: andre3d
author_rank: Contributor
timestamp: July 13, 2025, 03:49:30 pm
content: I don't know, but it only 3 resistor values."Upgrading this firmware requires recalibration of the three short-circuit resistors of 10 milliohms, 100 milliohms and 1Ω."

author: BillyO
author_rank: Super Contributor
timestamp: July 13, 2025, 04:32:50 pm
content: Quote from: andre3d on July 13, 2025, 03:49:30 pmThat was quoted from some obscure Chinese forum. I upgraded mine from 1.0.7 to 1.0.8 and it's still accurate. No change at all in accuracy.There is all sorts of crap coming up about this meter. In this tread someone said after upgrading to V1.0.8 it won't measure 10MΩ .. hogwash!!There sure is a lot of pure bunk about this meter.

author: andre3d
author_rank: Contributor
timestamp: July 13, 2025, 04:43:18 pm
content: Measure it at 1kHz.

author: BillyO
author_rank: Super Contributor
timestamp: July 13, 2025, 05:15:07 pm
content: Oh, FFS!Why would I want to do that?With every single LCR meter I have had the pleasure to work with, I get better resistance readings a lower frequencies.In this case it matches the Fluke 87V precisely. Which do you suppose is wrong?Okay, for the diaper war crowd, I'll do it. At 1KHz it reads 9.70MΩ All of 0.1% different. Wow! Yes! I can see how that counts as"But it doesn't measure 10M resistance at all and that's bad."

author: andre3d
author_rank: Contributor
timestamp: July 13, 2025, 05:24:03 pm
content: Set level 0.6V

author: BillyO
author_rank: Super Contributor
timestamp: July 13, 2025, 05:32:50 pm
content: Quote from: andre3d on July 13, 2025, 05:24:03 pmFor you, anything!Oh, holy feces Batman, he's found the smokin' gun!Back to 9.69MΩ Tired of this yet?

author: Aldo22
author_rank: Super Contributor
timestamp: July 13, 2025, 06:01:34 pm
content: Quote from: BillyO on July 13, 2025, 04:32:50 pmThere is a small offset in the lowest ranges.QuoteI don't know whether it is worth recalibrating.Maybe the 10mΩ range.

author: viktor63
author_rank: Contributor
timestamp: July 13, 2025, 06:23:42 pm
content: Today I received the toy with the firmware already installed 1.0.8

author: BillyO
author_rank: Super Contributor
timestamp: July 13, 2025, 06:28:29 pm
content: I don't know what to say. Why is mine spot on and yours is so different? (I'm assuming both pictures are the same resistor)

author: viktor63
author_rank: Contributor
timestamp: July 13, 2025, 06:30:15 pm
content: Yes. Large error in readings of 100 Hz and 1 kHz

author: viktor63
author_rank: Contributor
timestamp: July 13, 2025, 06:33:07 pm
content: Resistor 10Mohm 1%

author: Aldo22
author_rank: Super Contributor
timestamp: July 13, 2025, 06:50:09 pm
content: Some difference here ( v1.0.8 ), but not quite as bad.

author: BillyO
author_rank: Super Contributor
timestamp: July 13, 2025, 06:56:15 pm
content: Another test.This time a low resistance. I did a short calibration with the leads before doing this test. Unfortunately the Fluke does not have as much precision as the Zoyi, but the measurements agree within rounding and specifications.DUT is that bit of #14 wire measuring 2.3mΩ.

author: BillyO
author_rank: Super Contributor
timestamp: July 13, 2025, 06:58:51 pm
content: Quote from: Aldo22 on July 13, 2025, 06:50:09 pmThat's within specifications, but Viktor's is not.

author: GigaJoe
author_rank: Frequent Contributor
timestamp: July 14, 2025, 06:30:06 pm
content: made a coax cable connectors ... old cap. 560pF , 10%a difference comparing to enclosed onestable reading on 100 Hz , with original accessories jumping 595-600actual measure with coax , 100Hz - 569 , 100kHz - 570 ; no sense on movement or hand position ..( just a note , i forgot divider , bias and level incorrect , didn't notices, comparison i did with divider , level 0.6 bias -0 )waiting resistors ... need recalibrate it .... seems it like some factory default ... not specifically per device.( can it be possible to purchase in quantity , skipping factory calibration for a lower price)

author: BillyO
author_rank: Super Contributor
timestamp: July 14, 2025, 07:02:34 pm
content: There is so much wrong with that pictureNow you're going to cali-break it

author: GigaJoe
author_rank: Frequent Contributor
timestamp: July 14, 2025, 07:42:04 pm
content: what exactly i did incorrect ?

author: BillyO
author_rank: Super Contributor
timestamp: July 14, 2025, 07:49:25 pm
content: Quote from: GigaJoe on July 14, 2025, 07:42:04 pmWell, you mentioned a bunch of them yourself, but add to them that you are measuring a polystyrene capacitor in a mode designed for large electrolytic capacitors.Then, you measure a 10% tolerance capacitor and get a result well within specifications and claim that you need to recalibrate it. What makes you believe it needs re-calibration?And finally, you plan to do that recalibration with uncalibrated resistors.BTW, where are you getting these resistors?

author: GigaJoe
author_rank: Frequent Contributor
timestamp: July 14, 2025, 10:26:23 pm
content: well ...as i , mention "bias and level incorrect", offset actually indifferent ... need as much as possible amplituderesistors smd 2510 10ppm 0.1% i have 2 (last year) calibrated 34411A , 01A , so can measure voltage and current to calculate better resistance for low ohm, and direct measure for others . Low noise current source as well. Have precision 0.01 mV low noise voltage source up to 30V ... need to figure out about 60V ... I'm thinking I'm ok on this state ...

author: BillyO
author_rank: Super Contributor
timestamp: July 14, 2025, 10:40:02 pm
content: Quote from: GigaJoe on July 14, 2025, 10:26:23 pmSure...You didn't answer my other question though. Why do you think it's out of calibration?

author: GigaJoe
author_rank: Frequent Contributor
timestamp: July 14, 2025, 11:37:20 pm
content: well. i don't have any cap or inductance for precise comparisonbut i have set of 0.01% 0.25w through hole measure as Rsvalue F-100Hz F-100kHz100.001 107.43 99.021.00002K 0.9998 0.99202.00001K 1.9993 1.9807 ( this is special one may be affected by C or L )9.99926K 10.126 9.9491.0004M 0.897M 77.800K (approx)100 ohm kinda off, im thinking at 100Hz reactive resistance probably insignificant. It nicely measure 1K , the rest it kinda off ...im scratching my head about 1M result .... why so large difference for diff. freq.upd: after hitting range from auto to manual set 100K then 1M shows as 1.0004 and something 360K on 100kHz . seems software glitches ..

author: BillyO
author_rank: Super Contributor
timestamp: July 14, 2025, 11:56:17 pm
content: You should not be measuring resistors over 100KΩ with frequencies over 1kHz with this unit. It is not specified to be able to do that. RTFM!I'll bet all those resistors measure just fine and dandy at 1KHz, which is the most accurate range for resistors on this meter.It's amazing how everyone else is having issues with theirs yet the one I have my hands on seems perfectly fine.Anyway, it's just a toy, go ahead and play with it. When it's broken, throw it out, I guess.

author: viktor63
author_rank: Contributor
timestamp: July 15, 2025, 06:48:13 am
content: Good measurements ))

author: viktor63
author_rank: Contributor
timestamp: July 15, 2025, 06:52:45 am
content: Good resistor, good measurements ))

author: Aldo22
author_rank: Super Contributor
timestamp: July 15, 2025, 08:20:54 am
content: Quote from: GigaJoe on July 14, 2025, 11:37:20 pmThat's not the case for me.I measured an approx. 99Ohm resistor at 0.6V / Range:Auto / Model: Autofrom 100Hz to 100kHz:QuoteTry afactory reseton the original version and measure again.Don't use "REL".

author: viktor63
author_rank: Contributor
timestamp: July 15, 2025, 10:11:33 am
content: 100R 5%

author: Propretor
author_rank: Regular Contributor
timestamp: July 16, 2025, 04:54:36 pm
content: This disgrace occurs when trying to calibrate the device using a precision calibration resistor EE 0.25W 0.1% per 10 MOhm. Someone here at the forum argued that these resistances have no inductance. But I have no other explanation for this behavior of the device with this resistor:

author: andre3d
author_rank: Contributor
timestamp: July 16, 2025, 05:27:58 pm
content: You probably have a big gap between the contacts.

author: Aldo22
author_rank: Super Contributor
timestamp: July 16, 2025, 06:10:23 pm
content: Quote from: Propretor on July 16, 2025, 04:54:36 pmWhy Model:SER?Try Model:AUTO.

author: Propretor
author_rank: Regular Contributor
timestamp: July 16, 2025, 06:28:53 pm
content: Quote from: andre3d on July 16, 2025, 05:27:58 pmI have a normal gap. There are no such problems with smaller resistors.

author: Propretor
author_rank: Regular Contributor
timestamp: July 16, 2025, 06:30:20 pm
content: Quote from: Aldo22 on July 16, 2025, 06:10:23 pmIt does not matter whether the model is serial or parallel.

author: andre3d
author_rank: Contributor
timestamp: July 16, 2025, 06:40:10 pm
content: open calibration must not be performed. do a factory reset.

author: Aldo22
author_rank: Super Contributor
timestamp: July 16, 2025, 07:29:46 pm
content: Quote from: Propretor on July 16, 2025, 06:30:20 pmFor me it makes a big difference at 1kHz and 10MΩ.The manual says: "Resistance ≥ 10KΩ: Automatic, parallel".

author: Alphataurus
author_rank: Contributor
timestamp: July 16, 2025, 09:13:56 pm
content: 10 MΩ is at the limit of the specs, mine with v1.0.7 also behaves somewhat erratically. I don't know if it's only because of the HW, or the way the FW processes it also influences something.The following measurements are done with the resistor in the picture, what i know about it is that it is SMD and verified it is into 0.1% tolerance. I don't have kelvin clamps here, so 2-wire measurements.Factory defaults, resistor inserted directly into the 4mm connectors of the DQ02:100 Hz -> 10.3x and very rarely 10.0x appears.1 kHz -> 12.0x and very very rarely 10.2x appears.But if I use the cables (or the three 4mm adapters) from the picture:100 Hz -> Same as before, but 10.0x is displayed somewhat more frequently.1 kHz -> 10.2x and very very rarely 12.0x.Therefore, these big jumps in the measurements seem to be related to the capacitance of the connection lengths. Of course the higher the frequency the more it influences.If I calibrate it using that resistor, things improve quite a bit, but still not perfect, by inserting the resistor directly into the 4mm holes of the Zoyi:100 Hz -> 9.9x-10.0x and very rarely 10.3x1 kHz -> 10.1x alternating with 12.0xExtending the connection of the resistor as before, at 1kHz, 10.1x almost stable.

author: GigaJoe
author_rank: Frequent Contributor
timestamp: July 16, 2025, 10:47:45 pm
content: it seems for limits measurement like a pf, or 10M, need to set max signal amplitude - 0.6V and largest shunt as 100K ,10M at 100Hz in this case i do measure as 9.99 , 1K give 9.7M , 10K - 6.8M 100K - 680Kprobaly auto mode for shunt not always the best

author: BillyO
author_rank: Super Contributor
timestamp: July 16, 2025, 10:59:42 pm
content: Quote from: GigaJoe on July 16, 2025, 10:47:45 pmWhy are you measuring a 10M resistor at more than 1KHz?

author: frankvnk
author_rank: Newbie
timestamp: July 21, 2025, 08:24:51 am
content: Possible issue with the Hpot/Hcur and Lpot/Lcur slots?On my meter, the tabs don't close when the insulator spacer is removed.This means that a short calibration is not possible using only these tabs.Not usable with non-Kelvin leads as the floating input results in incorrect measurements. I didn't insert thick wires into the slots - never used them before.Relying solely on the "spring force" of the tabs is not good. There should be springs attached to the back of the tabs to push them together.This will also result in a lower contact resistance and improve grip on inserted leads.Anyone else noticed this?

author: SVS_Chip
author_rank: Newbie
timestamp: July 21, 2025, 09:19:50 am
content: Yes, my device had the same problem. I had to disassemble and bend the contacts. I don't know how long this will last.

author: Aldo22
author_rank: Super Contributor
timestamp: July 21, 2025, 09:49:30 am
content: Yes, unfortunately it's true.I don't know whether bending will help much.Either you close it with a metal sheet for 2-wire measurements, or you buy something like this:https://www.aliexpress.com/item/1005004382289251.html

author: frankvnk
author_rank: Newbie
timestamp: July 21, 2025, 12:13:57 pm
content: The jumper plugs are a nice solution (currently inserting shorting sheets into the slots).I also had a look at bending the tabs while i had it disassembled but i abandoned the idea given the construction.Attaching springs (or perhaps a decent foam) to the back of the tabs is an improvement.It's a pity that, despite all reviews, nobody ever mentioned this before (or perhaps i missed it) as it is important for 2-wire measurements.I sent an E-mail to zotektools about this issue. Waiting for a reply.

author: BillyO
author_rank: Super Contributor
timestamp: July 21, 2025, 01:45:55 pm
content: Folks, you cannot do a short calibration just by removing the insulating sheet. You MUST replace that with a copper shorting sheet or, less desirable, a bare copper wire. They don't supply one, so you have to buy one or make one to go between the "pot" and "cur" sections. All four leads need to be shorted together.Using the Kelvin leads, even ones that go into the slots, is not a substitute if you are testing components at the slots. Every time you switch measurement method, lead then slots, or slots then leads, you need to re-do the open and short calibrations to make up for the leads or the lack of leads. The other calibrations should not be need to be done as they are done at the factory.

author: Nospa
author_rank: Contributor
timestamp: July 21, 2025, 02:06:28 pm
content: Quote from: frankvnk on July 21, 2025, 08:24:51 amI didn't until you mentioned it - same thing on my device. Difficult to see without disassembly.Easy check:Cut a paper strip and try to insert it.If it just goes in w/o any resistance at all, the blades obviously don't touch.For now I'm going to apply copper tape on the stock isolation thingy to make it into a 'shorting thingy'...I've attached a step file containing a model of the original isolation bridge. Might be useful as a start to make a proper 'shorting bridge' or custom things in general.

author: BillyO
author_rank: Super Contributor
timestamp: July 21, 2025, 02:40:25 pm
content: Quote from: Nospa on July 21, 2025, 02:06:28 pmThe paper check sounds pretty good.Here the one I made using a piece of 1mm thick copper I got from AliExpress. Needs a little finishing in the keyhole and a little more taper on the insertion edge, but it's getting the job done.

author: BillyO
author_rank: Super Contributor
timestamp: July 21, 2025, 02:41:16 pm
content: Quote from: frankvnk on July 21, 2025, 12:13:57 pmPerhaps, like the one I have, theirs did not have this problem.

author: Nospa
author_rank: Contributor
timestamp: July 21, 2025, 03:05:05 pm
content: Actually I welcome the 'issue'. Saves me from having to insert the stupid strip for regular kelvin measurements.Now I just need to come up with a custom 4-wire set of 'pointy probes' for in-circuit testing which was the plan anyway.

author: Alphataurus
author_rank: Contributor
timestamp: July 21, 2025, 06:19:29 pm
content: The problem with the slots seems to be a manufacturing defect in some units, mine is fine so far.I've used the Ziboo kelvin clamps a couple of times and although the fit is very tight it doesn't seem to be a problem and the measurements seem pretty accurate.I don't have the original banana kelvin clamps, I ordered them but the seller didn't include them in the package. But I have used other 4-wire banana, good quality, but 1 meter long, and the extreme measurements are not good. The measurements made with 2 wires of 25 centimeters are better, and possibly improved by using a third wire for the guard.So far I have only made some quick measurements of a few components, when I have some time I will build 3-wire and 5-wire banana clamps to test, as I think I have the materials around. Then I will be able to do a more detailed comparison between them, and also between FW 1.0.7 and 1.0.8, and will see if there are significant differences in some measurements.What I do believe is that the midrange resistance measurements are quite accurate for the price of the equipment, and that the factory calibration is correct. For the 10MΩ calibration, I get slightly different results on each attempt, usually improving on the factory calibration. I find that this calibration is not robust and the readings during calibration are not consistent, just as they are not consistent when testing resistors of values near or past the spec limit.

author: SVS_Chip
author_rank: Newbie
timestamp: July 22, 2025, 07:14:57 am
content: Hello!The device has C and ECAP functions (electrolytic capacitors). In ECAP mode, the test level can be set to no more than 0.3V. What is the fundamental difference between them? The documentation does not provide any information about this. I could not find any information on the forum either. I have performed measurements of electrolytic capacitors in both modes, but I do not see any difference. Please provide an explanation.

author: Aldo22
author_rank: Super Contributor
timestamp: July 22, 2025, 08:20:48 am
content: Quote from: SVS_Chip on July 22, 2025, 07:14:57 amI think the essential thing is the bias that is automatically set in this mode to shift the sine wave completely into the positive range.Hence the limitation to 0.3V.

author: SVS_Chip
author_rank: Newbie
timestamp: July 22, 2025, 09:12:46 am
content: And yet, the topic of the ECAP function is not fully understood for me. Does this mean that electrolytic capacitors must be measured strictly in this mode? Or is this another opportunity to conduct additional tests with electrolytic capacitors? And regular measurements can be performed in C or AUTO mode. Am I understanding this correctly?

author: Aldo22
author_rank: Super Contributor
timestamp: July 22, 2025, 10:06:06 am
content: Quote from: SVS_Chip on July 22, 2025, 09:12:46 amI don't know any more than you do.In principle, electrolytic capacitors do not like reversed polarity. This is prevented with the bias.I don't know whether there are electrolytic capacitors that can be damaged by the voltage/energy supplied by this LCR meter.https://en.wikipedia.org/wiki/Aluminum_electrolytic_capacitor#Reverse_voltage

author: mawyatt
author_rank: Super Contributor
timestamp: July 22, 2025, 01:28:59 pm
content: Electrolytic Capacitors are unipolar (except for special versions) and can be damaged with "excessive" reverse bias. Excessive would need to be determined by the specific device, altho older Wet Slug Tantalums were often used with a small (under 1V) reverse bias or AC signal.In the case of an LCR Meter the test AC waveform will "reverse bias" the DUT on half the waveform, if this is small then the DUT will be OK and produce an acceptable measurement, larger AC waveforms may not.Having a dedicated special ECAP mode keeps the LCR test AC waveform unipolar and prevents any reverse bias to the DUT. If your LCR Meter doesn't have this feature, then apply a small DC bias to the DUT to keep the AC test waveform unipolar at the DUT, or in most cases just limit the amplitude of the AC test waveform. Our experience has been test AC waveforms below ~0.5 volt peak produce acceptable results with electrolytics and no DUT damage, where the electrolytic DUT isn't considered as a "precision" component or measurement, of course YMMV!!Best

author: BillyO
author_rank: Super Contributor
timestamp: July 22, 2025, 02:15:10 pm
content: Quote from: mawyatt on July 22, 2025, 01:28:59 pmYes, this.^^Try to avoid cali-breaking your LCR meter if measuring an electrolytic gives slightly different results on different meters.

author: ninodeves
author_rank: Contributor
timestamp: July 28, 2025, 08:49:34 pm
content: Quote from: frankvnk on July 21, 2025, 08:24:51 amExcuse me for saying this, but the tabs should not be closed; they should only close when the component to be measured is inserted. So it is not a manufacturing defect. If the tabs were always closed, instead of open, when you measure with 4 wires, the meter would measure incorrectly. Regards.

author: BillyO
author_rank: Super Contributor
timestamp: July 28, 2025, 09:05:02 pm
content: Quote from: ninodeves on July 28, 2025, 08:49:34 pmNo, they are very much supposed to be closed. That's why they give you the insulator insert for doing 4-wire measurements with leads. Also, if they did not touch you would not be able to do 2-wire measurements at all.

author: Propretor
author_rank: Regular Contributor
timestamp: July 29, 2025, 08:58:44 am
content: I would write like this: the contacts must be open when measuring according to a 4-wire measurement scheme and closed in other cases.

author: ninodeves
author_rank: Contributor
timestamp: July 29, 2025, 07:45:54 pm
content: Quote from: BillyO on July 28, 2025, 09:05:02 pmI insist again, the tabs should be normally open and when you insert the pins of the component to be measured into them, that is when you close the tab between the top and the bottom.

author: BillyO
author_rank: Super Contributor
timestamp: July 29, 2025, 08:03:52 pm
content: Quote from: ninodeves on July 29, 2025, 07:45:54 pmYou can insist all you like. That's not the case. In normal conditions they touch and that is How Zoyi designed them. Otherwise they would never have needed to include the insulating spacer to keep them apart for 4-wire measurements.All the other LCR meters with these sorts of sockets are the same, the contacts touch. So, you better contact DER, Keysight, GWinstek, Tekneka, UNT-I, etc.., etc.. and tell them they all got it wrong.Even the insertion fixture I have for my big bench LCR meter is the same. Contacts touch.You don't have one do you?A clue, I mean.

author: mawyatt
author_rank: Super Contributor
timestamp: July 29, 2025, 08:57:17 pm
content: 4 Wire Kelvin measurements are made with all the 4 wires being separateexceptwhen a resistor is connected between the Force and Sense pairs. This condition is sometime "seen" in Power Supplies where having a low valued resistor between the Force and Sense terminals in the supply prevents the supply from producing a high output when the Sense voltage isn't connected (Open Circuit). Because the Sense circuit impedance is very high the resistor doesn't introduced much error other than the output voltage at the intended load isn't sensed and thus the drop from the supply to load isn't compensated, which is the main intent in PS Kelvin Sensing.Maybe this Force to Sense resistor may be included in other equipment such as LCR Meters, but we don't know as we haven't investigated this.The DER-5000 apparently is somewhat unique in that it has split banana sockets as well as the usual slit-spade type connections. When the external measurement fixture (TL-21) is inserted the blades are split by the fixture and contact is made on both sides, the banana sockets are just filled with a plastic size plug for mechanical alignment and stability. Without the fixture one can directly insert a leaded component which the DUT lead splits the blades and makes the Force Sense contact thur the DUT leads, or insert a banana plug which directly shorts the split socket Force and Sense contacts for a 2 wire banana plug measurements (which the DER-5000 can only make unless special split banana plugs are used, but we've never seen these).The Zoyi has 4 banana sockets which allows 4 wire separate Kelvin cables whereas the DER-5000 has 3 (one is for Guard) so effectively 2, and can only do 2 wire measurements unless these special slit- banana plugs are utilized for 4 wire measurement which may require some sort of DER-5000 insulator insert like the Zoyi, altho we've never seen this.Best

author: Propretor
author_rank: Regular Contributor
timestamp: July 30, 2025, 06:17:10 am
content: Quote from: BillyO on July 29, 2025, 08:03:52 pmUnit UT612 does not have a 4-wire connection at all. Which, of course, is a pity.

author: Aldo22
author_rank: Super Contributor
timestamp: July 30, 2025, 08:21:01 am
content: Quote from: BillyO on July 29, 2025, 08:03:52 pmWell, the problem with the ZT-DQ0X isn't that it applies the wrong “philosophy,” but that these Kelvin sockets are simply mechanically weak, so you don't really know what you're getting.On my device, H is closed and L is open.H will probably change with usage as well.The banana connectors are solid, though.You can't complain at this price.

author: coromonadalix
author_rank: Super Contributor
timestamp: July 30, 2025, 09:42:18 am
content: on my dq 02the hpot/hcur and guard are somewhat open, faint openingand lpot/lcur seems closed ? i use the kelvin block cables when i use the lcr

author: Nospa
author_rank: Contributor
timestamp: July 30, 2025, 11:36:15 am
content: Unambiguous way to check if the springs are closed or open:With the device turned OFF. measure the resistance between Lpot & Lcur as well as Hpot &Hcur on the banana jacks.- when open the resistance is 10k on my DQ02- closed it obviously should be 0 ohmAlso there is only one guard, so the guard springs are 'shorted' on the pcb itself.On my exemplar all the springs are open with roughly a 0.18mm gap.I guess it is good enough to clamp component legs when inserted although I would have expected the springs closed with some preload to make better contact.

author: Alphataurus
author_rank: Contributor
timestamp: July 30, 2025, 12:48:23 pm
content: Another problem of blade separation could be the calibration for direct insertion of components into the blades. According to the Agilent Impedance Measurement Handbook (Figure 3-9), for an open calibration Hp and Hc must be joined together, as well as Lp and Lc. I don't know to what extent not complying with this will affect the calibration.Also note that the Hantek 1833c has the blades attached in the same way as the Zoyi (no separation), it seems normal considering that it only has banana plugs for 2-wire measurements.

author: mawyatt
author_rank: Super Contributor
timestamp: July 30, 2025, 03:43:20 pm
content: Quote from: Alphataurus on July 30, 2025, 12:48:23 pmThe Agilent reference is a good reference for folks to read and understand. If one understands how these LCR meters operate and acquire measurements, then the issue of terminals Hc, Hp, Lp and Lc become clear.When we created our "Open" Cal reference as shown for bench type LCR Meter use which have 4 separate BNCs for the mentioned terminals, we attached a short wire between Hc and Hp and another wire from Lc to Lp as required for a proper "Open" Calibration.It seems a lot of the discussion is centered around not having a good understanding of how these LCR Meters operate and what connections must or must not be made for a given 4 wire Kelvin or 2 wire DUT measurement and how a proper Open and Short Instrument Calibration is performed.Anyway, your Agilent reference is a must read for anyone interested in understanding what's going on with various LCR instruments and measurements, and a mandate for anyone wanting quality measurements!!BTW the reason we went to this extreme wrt to the Open and Short Calibration Fixtures was to have a good instrument repeatable reference from which to make measurements. Having the LCR Meter connections directly by BNC connectors without any cables or clips improves the reference uncertainty.Best

author: ninodeves
author_rank: Contributor
timestamp: July 31, 2025, 10:39:11 am
content: Quote from: BillyO on July 29, 2025, 08:03:52 pmI'm not going to argue anymore, as they say in my country, the big dog is yours.

author: Aldo22
author_rank: Super Contributor
timestamp: August 13, 2025, 10:49:37 am
content: I got a few (cheap) parts for the ZT-DQ02 from AE.A “Banana Plug Connector Short Circuit Double Adapter” to solve the problem of questionable Kelvin sockets for 2-wire measurements.And a few supposedly “non-inductive”0.1Ω and 0.01Ω resistors.I went with cheap 5% ones because we don't want to go overboard, and I figured one out of 10 would definitely be usable.And yeah, it looks like it is.

author: BillyO
author_rank: Super Contributor
timestamp: August 22, 2025, 07:00:50 pm
content: Better probe, better results?

author: Aldo22
author_rank: Super Contributor
timestamp: August 22, 2025, 10:01:40 pm
content: Quote from: BillyO on August 22, 2025, 07:00:50 pmBetter than what?I don't think so.Look, in the attachment, I measured an (almost) 1kΩ resistor once directly in the Kelvin sockets and once with the supplied probes.There is no difference (0.9909kΩ), so I don't think the supplied probes are bad, at least not for this measuring range.

author: hugo
author_rank: Regular Contributor
timestamp: August 22, 2025, 11:06:26 pm
content: Better reference resistor, better results?

author: BillyO
author_rank: Super Contributor
timestamp: August 22, 2025, 11:13:59 pm
content: Quote from: hugo on August 22, 2025, 11:06:26 pm

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 23, 2025, 12:26:59 am
content: Quote from: Aldo22 on August 22, 2025, 10:01:40 pmYou're correct that the measuring range limits the need for higher quality probes, but all you've shown is that the two testing methods you tried agree with each other. That means they're equally good, or equally bad.It's also worth noting that the device should be calibrated for each testing method, assuming it's capable of doing so.

author: BillyO
author_rank: Super Contributor
timestamp: August 23, 2025, 12:38:21 am
content: Quote from: KungFuJosh on August 23, 2025, 12:26:59 amIt is, although they have opened up way too much access to the calibration details allowing open, short and everything in between in decades from 10 mΩ to 10 MΩAnd what are people doing? Ordering set of cheap resistors to cali-break their meters.I had contacted Zoyi on the subject. They told me short and open are all you need when changing measuring apparatus. Everything else is factory calibrated. I suggested they close down the other options with a firmware release. Let's hope they do. Luckily the factory cal is stored in NVRAM, so can be recalled with a "factory reset".All I do is open and short, and as you can see, the results are fine.

author: BillyO
author_rank: Super Contributor
timestamp: August 23, 2025, 12:43:38 am
content: Quote from: KungFuJosh on August 23, 2025, 12:26:59 amSure, but that unit I got is one insertion to use, not 4 banana plugs plus an insulting insert for the internal fixture.It's so easy to use I'll probably never resort to the internal fixture unless absolutely necessary. limit my re-calibration efforts.

author: Cyclotron
author_rank: Unknown
timestamp: August 23, 2025, 02:08:22 am
content: Quote from: BillyO on August 23, 2025, 12:43:38 amI missed something, me thinks. Where did you get that probe set? Thanks

author: BillyO
author_rank: Super Contributor
timestamp: August 23, 2025, 02:16:02 am
content: Quote from: Cyclotron on August 23, 2025, 02:08:22 amhttps://www.aliexpress.com/item/1005004587014590.htmlLast item in the list. About $20 US.

author: Aldo22
author_rank: Super Contributor
timestamp: August 23, 2025, 07:15:02 am
content: Quote from: BillyO on August 22, 2025, 07:00:50 pmQuote from: KungFuJosh on August 23, 2025, 12:26:59 amYes, but the question was not whether the measurement was “accurate”, the question was about the influence of the probes.At 1kΩ, the supplied probes had no influence, so better probes would not make any difference.But anyway, to roughly check a 1kΩ resistor, you don't need an LCR meter with Kelvin clips.A DMM with a "REL" function is sufficient (Same resistor 0.9908kΩ).

author: Aldo22
author_rank: Super Contributor
timestamp: August 23, 2025, 07:24:00 am
content: Quote from: BillyO on August 23, 2025, 12:38:21 amAfter upgrading to 1.0.8, the lowest ranges 0.01Ω and 0.1Ω are no longer very accurate. Calibration is recommended for these.

author: BillyO
author_rank: Super Contributor
timestamp: August 23, 2025, 02:19:15 pm
content: Quote from: Aldo22 on August 23, 2025, 07:24:00 amAn yet, the results I get are just fine even though I did not resort to re-cali-breaking my meter.To be fair, I was told by Zoyi that it is possible that a firmware upgrade might possibly require a re-calibration of the .1Ω and .01Ω. However, they also said that this is not the case with 1.0.8.Where did you hear this?

author: Aldo22
author_rank: Super Contributor
timestamp: August 23, 2025, 02:33:53 pm
content: Quote from: BillyO on August 23, 2025, 02:19:15 pmI didn't hear this, I measured it, and you thanked me for the contribution (Thanks for that).https://www.eevblog.com/forum/testgear/new-lcr-meters-zoyi-zt-dq01-and-zoyi-zt-dq02-(march-2025)/msg5976975/#msg5976975

author: BillyO
author_rank: Super Contributor
timestamp: August 23, 2025, 02:42:38 pm
content: I usually thank someone if they take the time to reply directly to me. If you recall, I did not have the problem, so not sure what happened with yours.

author: Aldo22
author_rank: Super Contributor
timestamp: August 23, 2025, 02:45:16 pm
content: Quote from: BillyO on August 23, 2025, 02:19:15 pmMy tip: Buy 10 cheap, non-inductive 0.1Ω and 0.01Ω resistors and measure which one is best using the factory calibration or any other method.Then do the upgrade and recalibrate these two ranges. Done.You don't need expensive references for this.See:https://www.eevblog.com/forum/testgear/new-lcr-meters-zoyi-zt-dq01-and-zoyi-zt-dq02-(march-2025)/msg6010371/#msg6010371

author: mawyatt
author_rank: Super Contributor
timestamp: August 23, 2025, 02:48:38 pm
content: When measuring very low value Z components be sure to place the Kelvin Clips tips in the same location when comparing results!! The DUT leads themselves can add to the measurement when one is looking at lower digits in the few uΩ regions. Best to place the Kelvin clips as close to the DUT body leads as possible for good repeatability and comparisons. Sometimes scraping the body encasing residue from the leads close to the DUT body is necessary.When doing a Zero/Short calibration with these type inexpensive narrow snout Kelvin Clips (not the expensive wide mouth types) be sure to have the Clips Hc and Lc directly connect and the Hp and Lp directly connect. The reason is this allows the test current to flow from Hc thru to Lc and then the voltage sensing Hp and Lp which draws no current to sense the voltage at the Hc and Lc junction. Do not allow test current to flow thru either the Hp or Lp tips. This is how Hioki recommends using their Kelvin Clips. We label the Hc and Hp Kelvin tips and Lc and Lp tips on our inexpensive Kelvin Clips (the better Hioki and Tonghui Kelvin Clips have this already labeled) so we know which is which when making quality measurements.Best

author: BillyO
author_rank: Super Contributor
timestamp: August 23, 2025, 03:00:08 pm
content: Thanks Mike,Not sure that a mm or so in doing the short calibration is going to make a huge difference to this meter, but I'll measure and mark which lead is which for future consideration.I'm usually not all that concerned about a few uΩs. I'm just a long retired hobbyist. The point of all this, at least from my perspective, is this little Zoyi toy is pretty accurate .. for use by the average hobbyist.

author: Aldo22
author_rank: Super Contributor
timestamp: August 23, 2025, 03:03:07 pm
content: Quote from: mawyatt on August 23, 2025, 02:48:38 pmThank you.With the form factor of the resistors I used and the direct insertion into the Kelvin sockets, there is hardly any room for variation.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 23, 2025, 03:49:30 pm
content: Quote from: Aldo22 on August 23, 2025, 07:15:02 amThose are the same things.With low enough resolution, it's harder to tell the difference if something isn't terrible.

author: mawyatt
author_rank: Super Contributor
timestamp: August 23, 2025, 04:09:02 pm
content: Quote from: BillyO on August 23, 2025, 03:00:08 pmWe're retired as well, hoping to last long enough to have some more "fun"This doesn't cost anything and can improve results for any measurement level!! BTW using a conductive shielded base (we use our PCBrite base plate) can improve Kelvin Clip measurements with high Z components, just connect the shielded base to the Guard or Shield terminal on your LCR Meter and make the Kelvin Clip measurements above the shield.These Zoyi LCR Meters seem to be a great value!! If we didn't have so many meters now we would probably get one.Best

author: mawyatt
author_rank: Super Contributor
timestamp: August 23, 2025, 04:11:33 pm
content: Quote from: Aldo22 on August 23, 2025, 03:03:07 pmThen to compare with the Kelvin Clips make the clip contact where the leads insert into the meter Kelvin blades, this should include ~ the same DUT component lead effects.Best

author: Aldo22
author_rank: Super Contributor
timestamp: August 23, 2025, 04:32:23 pm
content: Quote from: mawyatt on August 23, 2025, 04:11:33 pmYes, that's true, but the wires of the resistor are quite short, so not much can go wrong.

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 23, 2025, 05:52:21 pm
content: Quote from: Aldo22 on August 23, 2025, 04:32:23 pmWhat does the X mean? Why is it inconsistent?Position and depth in the clip contacts makes a difference.

author: Aldo22
author_rank: Super Contributor
timestamp: August 23, 2025, 06:07:34 pm
content: Quote from: KungFuJosh on August 23, 2025, 05:52:21 pmIt is the reactance. A secondary parameter.I did not intentionally select it for this measurement.https://en.wikipedia.org/wiki/Electrical_reactance

author: mawyatt
author_rank: Super Contributor
timestamp: August 24, 2025, 01:12:15 am
content: Quote from: KungFuJosh on August 23, 2025, 05:52:21 pmThis is part of the R +-jX parameter. If + then inductive with value of 2*pi*F*L, if - then 1/(2*pi*F*C). In the case of X = 0.0042Ω @ 1KHz, then L is ~668nH, often this is referred as ESL.Best

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 24, 2025, 01:56:19 am
content: Quote from: KungFuJosh on August 23, 2025, 05:52:21 pmYes, thank you. What about the second question?If the test setup is good, and the connections are properly compensated, shouldn't we find repeatable results, even if the parameters are secondary...or quaternary?

author: BillyO
author_rank: Super Contributor
timestamp: August 24, 2025, 02:32:55 am
content: Hmm, well that little Hikoi toy cost a couple of dollars more than the Zoyi, me thinks.Nice lab you got going there!

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 24, 2025, 03:21:00 am
content: Quote from: BillyO on August 24, 2025, 02:32:55 amThanks. The fixtures cost more than the Zoyi, but that's a different story.The question remains with the inconsistency on the Zoyi meter. Is it because it's a low budget meter, or because of the test conditions, or test setup? Is it capable of producing consistent measurements?Perhaps the short DUT leads work against consistency in this case if they can't get better contact on the blades in the meter. 🤷

author: BillyO
author_rank: Super Contributor
timestamp: August 24, 2025, 03:54:07 am
content: Quote from: KungFuJosh on August 24, 2025, 03:21:00 amThat I can't answer. I don't seem to see the problems others are experiencing with this thing. However, the consistency you are seeing may have something to do with the quality of the equipment you are using. My measurements with this (when I do them) are usually done one way. Before, it was with the built in fixture, from now on it will be with that new probe/fixture/lead set I got ($20). If I measure the same resistor/cap/coil with it twice, I get the same result. Comparing that to the internal fixture, it's pretty close on the main parameter, but X is a little off. Not as bad as Aldo's results, but a little off. I put that all down to the "economy" grade meter and fixtures. My little ET4410 is far more consistent and I spent more on the fixtures for it.Lately I've been tempted to upgrade that to a ET3501 .. we'll see.Trying to keep the TEA virus at bay...

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 24, 2025, 05:19:15 am
content: Quote from: BillyO on August 24, 2025, 03:54:07 amGood luck with that.

author: Aldo22
author_rank: Super Contributor
timestamp: August 24, 2025, 07:25:25 am
content: Quote from: KungFuJosh on August 24, 2025, 03:21:00 amI will check this later.All I can say for now is that I didn't calibrate it (open, close) before switching to measuring with the Kelvin clips.I was only looking at the resistance measurement and it didn't seem necessary for that.EDIT:I took a look at it. I certainly lack experience and theory, but since these resistors in the photos above are non-inductive, I think we are reaching the measurement limit of this device.“Normal” resistors show roughly the same X and Phase values whether they are plugged into the sockets or the Kelvin clip.But it always depends on the measurement frequency.As a layman, I don't know what to make of it.

author: mawyatt
author_rank: Super Contributor
timestamp: August 24, 2025, 03:00:59 pm
content: You should always do and Open/Short Calibration before measurement sessions, especially if/when changing the measurement fixture. Kelvin Clips have long leads back to the meter, these introduce delays/phase shift which needs to be calibrated out, some of the better lab grade LCR bench meters have a cable length parameter just for this purpose.Best

author: mawyatt
author_rank: Super Contributor
timestamp: August 24, 2025, 03:20:22 pm
content: Quote from: Aldo22 on August 24, 2025, 07:25:25 amYou should redo those measurements of the non-inductive resistor with proper prior Open/Short Calibrations . The 668nH we calculated from the X value seems excessive for any physically small resistor unless a wire wound, which apparently your resistor isn't from the image.Best

author: Aldo22
author_rank: Super Contributor
timestamp: August 24, 2025, 05:02:32 pm
content: Quote from: mawyatt on August 24, 2025, 03:20:22 pmThanks.I tried that, but the secondary parameters are hopeless with these small non-inductive resistors.Like:Direct: Rs=0.0097Ω, X=0.0008Ω, θ=0.49°, D=120, Q=0.0093Kelvin: Rs=0.0096Ω, X=0.0056Ω, θ=3,14°, D=18.3, Q=0.05With a “normal” 46.x Ohm resistor, the differences are much smaller in percentage terms. See images.

author: mawyatt
author_rank: Super Contributor
timestamp: August 24, 2025, 05:06:36 pm
content: Here's something to consider when making quality Kelvin Clip Measurements with the inexpensive narrow "snout" clips.The LCR meter can be modeled (simple model) as voltage source V with source impedance Rs and the Kelvin Clips and Cable as with series resistors representing the driving cable and connectors (RHC and RLC) and the Kelvin Clip Tip resistance (RHCT and RLCT). The LCR Potential (also called Sense) cable and connectors (RHP and RLP) and the Kelvin Clip Tip resistance (RHPT and RLPT).The contact between the HC and LC Kelvin Tips is RContact and the HP and LP Tips is HPT and LPT respectively.The correct Zero Ohm Short Kelvin Connection according to Hioki is clamp the HC Kelvin Tip to the LC Kelvin Tip then the HP Tip to the other side of the LC Tip and the LP to the other side of the HP tip. Thus a HC-LC-HP-LP connection at the Kelvin Tips. A simple analysis shows this connection arrangement yields an ideal Zero Ohm Result as sensed by the LCR Meter.The incorrect connection of HC-LP-HP-LC produces a result that is not ideally zero like above but the contact resistance of the HP and LP Tip connections.Anyway, depending on the LCR Meter resolution and Kelvin Clip quality this may make a difference in low Z component measurements and doesn't cost anything to do properlyBest

author: KungFuJosh
author_rank: Super Contributor
timestamp: August 24, 2025, 07:40:41 pm
content: In the case of my L2000 kelvin probe, Hioki makes it harder to screw up. The directions are clear, the probes are marked, and they can only be connected one way to the meter.For separated 4-wire connectors like on the Zoyi, you should mark the connectors so they're plugged in and compensated the same way every time.

author: GigaJoe
author_rank: Frequent Contributor
timestamp: September 02, 2025, 03:37:44 pm
content: 10 milliohm was challenge , for 0.01 0.1 and 1 I use the same fixture that i made for Zoyi LCR to make transfer reference , set .01 on ref. DMM 4W then disconnect and connect to LCR meterfor .01 .1 i use current sense SMD resistors 10ppm , basically ok for , 0.010 in fact appears as 0.014, add some SMD in parallel to make 0.011 with come copper wire then change soldering point on this wire i adjust of milliohm ..gosh ... got 0.01006 and decided it OK . DUT LCR shows 0.014 ...the problem what i see in this procedure .. reference let say 1.0000K but scale 8.0000K we have an error accumulation ..did someone try to test resistance for example , to see how linear the scale , or it doesn't make sense ?

author: mawyatt
author_rank: Super Contributor
timestamp: September 02, 2025, 06:29:32 pm
content: Quote from: mawyatt on August 24, 2025, 05:06:36 pmHere's an example of the above correct short calibration with Kelvin Clips and how it affects results. LCR Meter is Hioki IM3536 using Tonghui TH26011CS Kelvin Clips.Shorts were performed by shorting Kelvin Clips at tip in Hc=Lc=Hp-Lp proper format and performing a Zero Calibration. Then measuring results (Correct), reversing Clips Hc-Lp-Hp-Lc (Reversed), then returning clips to proper format (Reconnect). Note how the reversed (improper) measurements show for a Zero Ohm Kelvin Short!!BTW the Kelvin Clips were cleaned prior to any calibration and tests.Best

author: mawyatt
author_rank: Super Contributor
timestamp: September 02, 2025, 06:46:13 pm
content: The we did anImproper Zero Ohm Calibration Hc-Lp-Hp-Lcwith same setup as above. Then repeated the sequence of measurements, reversed Kelvin Clips Hc-Lc-Hp-Lp (ImpReversed {proper connected}), then reconnected (ImpReconnect) as initially Hc-Lp-Hp-Lc. Note the big difference when reconnecting again, this proved difficult and the results were varying considerably, the most stable readings were the reversed (proper Kelvin configuration)!!!This test setup clearly demonstrates the advantages of doing a proper Kelvin Zero Ohm calibration, rather than haphazardly connecting the Kelvin Clips when doing a Zero CalibrationBest

author: mawyatt
author_rank: Super Contributor
timestamp: September 02, 2025, 07:11:03 pm
content: Reran the testing in #423 above with Proper Kelvin Clip Zero Ω Calibration. Note the repeatability between these runs and the between reconnects, and note the reversed (Improper) clip results!!! Also pay attention to the LCR Meter DUT (Zero Ω) Voltage and Current readings for the AC R and the DC R.This should clearly illustrate the advantage of the proper Hc-Lc-Hp-Lp Kelvin Clip orientation for Zero Ω Calibration and help explain (see analysis in #423 above) why many folks struggle with low Z component measurements, especially with repeatability. Folks can experiment with this technique on their LCR Meters to see the effects, and it doesn't cost anythingBest

author: GigaJoe
author_rank: Frequent Contributor
timestamp: September 02, 2025, 11:55:22 pm
content: great point on proper nulling and connection , actually repeatable even on subj meter ...and what i measured ... for resistance, wonder about linearity , reference resistance are 0.01% or better , all of them are X.0000XX (kOhm) XXX.00X (Ohm)( this is after i did unit recalibration )kOhm Ohm0.0000 0.0073 ( consider offset )1.0000 99.992.0000 199.993.0000 299.994.0000 399.954.9997 499.696.0018 599.776.9992 699.997.9999 799.82interesting .... why 6K off ..

author: Cyclotron
author_rank: Unknown
timestamp: September 03, 2025, 05:40:40 pm
content: Quote from: BillyO on August 23, 2025, 02:16:02 amThese are fantastic for the price. I've validated that they are true 4 wire to tip. It makes sense that short calibration be done correctly. So I need to figure out a good way to label the clips so I know which ends are which, and likely print a label to put on the back to remind me of the proper orientation.Thanks again for the link!

author: Aldo22
author_rank: Super Contributor
timestamp: September 04, 2025, 08:28:32 am
content: Quote from: Cyclotron on September 03, 2025, 05:40:40 pmDo these have any advantages in measurement compared to the 4-wires with banana plugs?If so, why?

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 04, 2025, 02:45:45 pm
content: Quote from: Aldo22 on September 04, 2025, 08:28:32 amAnything that forces a consistent connection will improve repeatability.

author: Aldo22
author_rank: Super Contributor
timestamp: September 04, 2025, 02:57:39 pm
content: Quote from: KungFuJosh on September 04, 2025, 02:45:45 pmYes, you may be right.I've also marked my Banana Kelvins with leftover oscilloscope probe rings.I'm just not entirely sure if we're not exaggerating a little here.With all due respect, is the $60 Zoyi LCR meter really worth all this consideration?In my opinion, it's not that accurate or stable.

author: KungFuJosh
author_rank: Super Contributor
timestamp: September 04, 2025, 03:15:27 pm
content: Quote from: Aldo22 on September 04, 2025, 02:57:39 pmIf accuracy or stability matter at all, then it matters. If the device is already working against accuracy and stability, then you don't want to make it worse with a poor test setup.Regardless of the equipment, a bad test setup will make things worse. Doesn't matter if the meter cost $2 or $2M. I'm not aware of a device at any price point that can fix what I screw up for me. Not yet anyway.

author: coromonadalix
author_rank: Super Contributor
timestamp: September 04, 2025, 03:51:20 pm
content: Quote from: KungFuJosh on September 04, 2025, 03:15:27 pm+1 on that, so many things can go wrong, even some kelvins clips are a total waste of $you want to be serious, buy serious stuff, and sadly the prices goes with that ... not mere toys like the Zoyi or Fnirsi .. even the DE-5000 has it's limits, many hand helds tooit's been a while since FW 1.08, no updates, Zoyi have slowed down ... that's a signThe only things who could help is to tell Zoyi all the found problems and hope they decide to solve it

author: Aldo22
author_rank: Super Contributor
timestamp: September 04, 2025, 04:59:53 pm
content: That's not the problem.For that money, I expect nothing more than a better toy. What else is Zoyi supposed to deliver?The question was, how much money should you invest in accessories for this toy?$20 for non-inductive precision resistors for calibrating a range that has 3% accuracy? Nonsense.Extra Kelvin clips again, after I already have some?Does that make sense?

author: coromonadalix
author_rank: Super Contributor
timestamp: September 04, 2025, 05:47:14 pm
content: @AldoI paid for the ones who where linked here, they are good, costed me 30 ish something $i would say, i total around 130$ usd for the Zoyi dq02 kit + supplemental kelvins .. witch is fine for me, i did not order kelvin tweezersThe DE-5000 costed 35$ more at the time w TL21 probes, and a few weeks later you could grab the full kit (no suitcase) for a few $ moreI would say around or under 200$ it is somewhat okay, it is MY limit BUT you may get some better lcr but with or no acessoriesFinallyAround 250 - 260 $ i would personally switch to bench ones ... once again this is MY personal limit not yours ?

author: Aldo22
author_rank: Super Contributor
timestamp: September 04, 2025, 06:17:04 pm
content: Quote from: coromonadalix on September 04, 2025, 05:47:14 pmThat's quite a lot.I paid US $61.96 total for my DQ02 with Kelvin clips (Banana).

author: EU1
author_rank: Regular Contributor
timestamp: September 16, 2025, 03:33:17 am
content: I recently got ZT-DQ02, and I noticed that its buzzer is very quiet.Is this just an issue with my unit, or are all ZT-DQ02 meters like that?

author: BillyO
author_rank: Super Contributor
timestamp: September 16, 2025, 03:54:45 am
content: Haven't noticed. Either it's fine or I don't care. Moreover, I'm almost deaf, so ... it's most likely I don't care.I'm busy for the next day or so, but after that I could get it out and do a deep dive into this crucial aspect.

author: EU1
author_rank: Regular Contributor
timestamp: September 16, 2025, 04:18:48 am
content: Quote from: frankvnk on July 21, 2025, 08:24:51 amExactly the same as mine. Since I almost never use the slots to measure TH components, it's not really a big problem for me.

author: Aldo22
author_rank: Super Contributor
timestamp: September 16, 2025, 08:45:49 am
content: Quote from: EU1 on September 16, 2025, 03:33:17 amYes, the buzzer is rather quiet, but does it have any function other than indicating that a button has been pressed?I think that in tolerance mode, it should sound when the measured value is within the tolerance range (PASS).

author: yo0
author_rank: Regular Contributor
timestamp: September 17, 2025, 05:18:15 am
content: seems there is a new software for dq01 and dq02, it is in Chinese, probably will be an English version laterhttp://www.szzotek.com/h-col-159.htmlMD2以及DQ01,02上位机2025.9.10.zipbest regardsPio

author: yo0
author_rank: Regular Contributor
timestamp: September 24, 2025, 05:09:14 am
content: seems there are new firmwares for dq01 and dq02, dated September 23http://www.szzotek.com/h-col-159.htmlZT-DQ02固件2025.9.23.zipZT-DQ01固件2025.9.24.ziptranslation from the png image at the zip file: DQ02's fixed the problem of inaccurate measurement of megaohm resistance at 1khz.best regardsPio

author: coromonadalix
author_rank: Super Contributor
timestamp: September 24, 2025, 08:14:36 am
content: "they" are too lazy to give it a REAL name loll v1.1.0 for both models DQ01 DQ02

author: Aldo22
author_rank: Super Contributor
timestamp: September 24, 2025, 02:38:10 pm
content: Yeah, v1.1.0.Has anything else changed?There are two steps from v1.0.8 to 1.1.0.Have the SCPI capabilities been improved?

author: ander7
author_rank: Contributor
timestamp: September 26, 2025, 06:38:45 am
content: Quote from: Aldo22 on September 24, 2025, 02:38:10 pmI don't remember which commands were working in v1.0.8 but in v1.1.0 the following commands are working: FETCh?, FREQuency, BIAS:VOLTage, APERture, FUNCtion:IMPedance:MAIN, FUNCtion:IMPedance:Model, FUNCtion:IMPedance:RANGeFirmware contains more SCPI commands but I haven't tried them yet.

author: ander7
author_rank: Contributor
timestamp: September 27, 2025, 12:03:15 pm
content: SCPI commands for comparator : COMParator, COMParator:NOMinal PARAM, COMParator:ERRor PARAMFew other strings are present in firmware:DATA:BLOB PARAM - no idea what it can beUSeRERRor - trigger 10,"Custom error; Custom error message..."ERROR_FALLBACK - trigger -400,"Query error"CHARData PARAM PARAM - without params -100,"Command error; Required 2 arg, got 0."

author: yo0
author_rank: Regular Contributor
timestamp: October 15, 2025, 12:48:18 am
content: another firmware update:http://www.szzotek.com/h-col-159.htmlhttps://download.s21i.co99.net/8164272/0/0/ABUIABBPGAAgjNi2xwYou8y-zAY.zip?f=DQ01%E5%9B%BA%E4%BB%B62025.10.14.zip&v=1760406540https://download.s21i.co99.net/8164272/0/0/ABUIABBPGAAgpti2xwYopZT9rwE.zip?f=DQ02%E5%9B%BA%E4%BB%B62025.10.14.zip&v=1760406566The firmware upgrade of DQ01 02 fixes the problem that OL is not displayed at no loadbest regardsPio

author: Aldo22
author_rank: Super Contributor
timestamp: October 15, 2025, 10:02:10 am
content: Quote from: yo0 on October 15, 2025, 12:48:18 amSeems to work (v1.1.1).

author: Fyfar
author_rank: Newbie
timestamp: October 18, 2025 09:57:51 am
content: Has anyone encountered an issue with updating the firmware on a DQ02?My device just hangs on USB-Boot 0% and nothing happens.The disk appears in the system, I copy the .bin firmware file there (I tried 1.1.1 and 1.0."8"), and nothing happens.When I reboot, it just stays on the same firmware it was on before.

author: Aldo22
author_rank: Super Contributor
timestamp: October 18, 2025 10:17:36 am
content: Quote from: Fyfar onYesterdayat 09:57:51 amNot for me.I've upgraded and downgraded probably 20-30 times, and it has always worked smoothly.Maybe try a different USB cable?

author: Fyfar
author_rank: Newbie
timestamp: October 18, 2025 02:42:42 pm
content: Quote from: Fyfar onYesterdayat 09:57:51 amI managed to update the device via a Linux (I have a media server running Linux).It didn't work via MacOS; the firmware file wasn't physically copied to the device. The file itself was displayed, but it wasn't physically there. Apparently, macOS copied the file attributes, but couldn't copy the file itself.So if anyone else has problems with the update and you have macOS, try Linux or Windows machine.

author: Candid
author_rank: Regular Contributor
timestamp: October 18, 2025 07:46:37 pm
content: Same for me, does not work with MacOS had to rea-animate our Windows PC.

author: ninodeves
author_rank: Contributor
timestamp: October 18, 2025 09:23:46 pm
content: How is version 1.1.1 of the Zoyi DQ02 going?

author: Aldo22
author_rank: Super Contributor
timestamp: «Reply #453 on:Todayat 09:28:23 am »
content: Quote from: ninodeves onYesterdayat 09:23:46 pmWhat exactly do you mean?See:https://www.eevblog.com/forum/testgear/new-lcr-meters-zoyi-zt-dq01-and-zoyi-zt-dq02-(march-2025)/msg6070025/#msg6070025