OWON XDM1041 the unknown multimeter... - Page 1
Forum section: electronics / testgear

author: Scrachi
author_rank: Contributor
timestamp: February 25, 2021, 08:53:04 am
content: Hi,I've found on ebay the bench multimeter OWON XDM1041 :https://www.ebay.fr/itm/OWON-XDM1041-3-7in-LCD-Mini-Desktop-Digital-Multimeter-True-RMS-Tester-Meter-New/164717198621?hash=item2659e8fd1d:g:ARwAAOSwLYRgM4M~But I don't find any information about it outside of the ebay product description, I've also checked on the Owon website but no info about it. I've sent an email to the Owon contact to try to get info, no reply yet.Comparing the specs, they are pretty close to the Owon xdm2041.Someone know this product ?Thanks.

author: paf
author_rank: Regular Contributor
timestamp: February 25, 2021, 09:30:33 am
content: Some info here:https://www.messgeraete-chemnitz.de/messtechnik/multimeter/tischmultimeter/1802/owon-xdm1041-tisch-multimeter-trms-mit-lcd-display-und-speicher

author: Fungus
author_rank: Super Contributor
timestamp: February 25, 2021, 10:00:39 am
content: Certainly a nice form factor...Only two or three hits on google, maybe it's a very new model.

author: Scrachi
author_rank: Contributor
timestamp: February 25, 2021, 12:31:37 pm
content: Thanks for the link.Yes it seems to be a new model, I like the small size of the box instead of the big box of the usual bench multimeters. I will wait if I can find more info/review of it but I think it can fit pretty well in my small lab...

author: Scrachi
author_rank: Contributor
timestamp: February 27, 2021, 09:27:09 am
content: Hi,I've just got the confirmation from Owon it is a new model:Owon email : "it is a new one, you will see on our website later."

author: maxwell3e10
author_rank: Frequent Contributor
timestamp: March 01, 2021, 05:48:49 am
content: It's a nice form factor and inexpensive. Unfortunately, just like for XDM2041, they probably will disable all fancy functions, like math statistics and trend chart. So its no better than a hand-held, although there is value in having the multimeter always on. A better choice would be to keep analysis functions to take advantage of the nice LCD display. That would set it apart from other simple bench meters.

author: Mp3
author_rank: Frequent Contributor
timestamp: March 01, 2021, 07:49:53 am
content: I also noticed this recently and was curious if it had anything to offer over one of the East Testers, which gets constant use in my lab and I love.

author: Scrachi
author_rank: Contributor
timestamp: March 01, 2021, 02:06:23 pm
content: Yes for the moment I don't find any specific info about the features. I'm waiting for the "official" Owon presentation to get the user manual and check all features.

author: EEVblog
author_rank: Unknown
timestamp: March 10, 2021, 12:37:23 pm
content: Just stumbled across this myself on ebay.I kinda like the look of it!Shame it's not battery powered.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 10, 2021, 03:27:39 pm
content: same footprint as a scope it seems ??Damn gonna click to buy one arrr will i or not lollAround 200$ cad shipping included, seems good to me

author: Scrachi
author_rank: Contributor
timestamp: March 10, 2021, 04:24:49 pm
content: I regularly check if I can find the user manual or an official presentation on the Owon site but nothing yet... It will be cool if they can have a measure logging function.Just bad, they do not have 4 wire resistor measurement...Who will click on "buy" first?

author: tunk
author_rank: Super Contributor
timestamp: March 10, 2021, 04:31:04 pm
content: In the photo above, professionals at work? - do I see a DT830B multimeter?

author: msquared
author_rank: Regular Contributor
timestamp: March 10, 2021, 06:15:26 pm
content: Punched the buy button last week.I think the form factor will be perfect for probing and glancing up without having to move my eyes to far away. I known it can be done with a bench meter or hand held but bench meters are big and deep and handhelds are usually at a funky angle when sitting on the tilting bale.And like that it has a real IEC cord for power and I don't have to deal with batteries or keeping track of the right plug pack. (sorry Dave)I wouldn't expect it to have great protection or accuracy but it should be good for basic troubleshooting and probing around an Arduino.Also in the past I've gotten really good support from Owon for one of their USB scopes so I have some confidence that if there are any issues they'll standby their products.All yet to be seen. If I get it first I'll post pictures of the innards and let the real experts post their analysis and opinions.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 10, 2021, 10:48:15 pm
content: Tons of sellers with timed offers ... witch one i should use or buy damnThe cheapest price is around 125$ usd with a 49 cent shipping loll and the others around 150$ usd with 17$ usd shippingAnd the surprises are in the handling time, most says 10 days after the payment is received and some goes up to 21 days

author: EEVblog
author_rank: Unknown
timestamp: March 12, 2021, 12:07:37 pm
content: Quote from: msquared on March 10, 2021, 06:15:26 pmAs with almost all benchtops regardless of price, it's only CAT II rated. But good enough for basic mains bench work.

author: wraper
author_rank: Unknown
timestamp: March 12, 2021, 12:13:52 pm
content: Quote from: Scrachi on February 25, 2021, 12:31:37 pmThere is nothing nice about it if you intend to use it as a bench meter. It will be pushed back when you try pressing any button, so you will need to hold it with another hand when pressing buttons.

author: Fungus
author_rank: Super Contributor
timestamp: March 12, 2021, 01:02:01 pm
content: Quote from: wraper on March 12, 2021, 12:13:52 pmPut your hand on top and press with the thumb.Pressing with index finger will be uncomfortable anyway at that height/angle.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 12, 2021, 03:18:40 pm
content: add concrete in it loll it wont move

author: robert.rozee
author_rank: Frequent Contributor
timestamp: March 13, 2021, 04:13:21 am
content: one could possibly 3d-print an alternative back housing, with extra length containing batteries and/or a lead weight, space for storing leads, carry handle, etc.i look forward to seeing a teardowncheers,rob :-)

author: DaneLaw
author_rank: Frequent Contributor
timestamp: March 14, 2021, 01:37:42 am
content: Many ways to put it somewhat stable on the desk.even a crude pair of silicone feet will prevent it from sliding around to much, otherwise you have this tape'ish rubber-like materiel, you can put underneath that almost grap the surface and if it gets dirty you can take it off and wash it and its good as new.also recall its that materiel they are now fitting on products like Insta360 Go2 wall-mounts for the camera and no actual adhesive, just very grippy rubberlike materiel. you can put behind a given product.Same with RC and batteries on quads so the LIPO aint sliding.It seems they have come a long way since those silicone pads, you could use on your deck in the car for phones and coins..

author: Microcheap
author_rank: Frequent Contributor
timestamp: March 16, 2021, 08:39:29 am
content: I've contacted Owon asking more details about this new meter and they sent me a spec sheet with some more information, including a picture of the inside (see pdf attached. I had split the file as it was a bit over the forum's 4MB limit).It looks interesting, at least more useful than the AN888S but BW is only 1kHz and the dual display only shows VAC + Hz. Apparently, they are planning to update the serial communication to USB soon.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 16, 2021, 09:34:16 am
content: 1khz ac bandwidth seriously ?? Any serious company should have a 100khz on any modern meter

author: Scrachi
author_rank: Contributor
timestamp: March 16, 2021, 10:10:51 am
content: Thanks for the PDF very useful, so the functions are very similar with the OWON XDM2041

author: robert.rozee
author_rank: Frequent Contributor
timestamp: March 16, 2021, 10:30:55 am
content: Quote from: coromonadalix on March 16, 2021, 09:34:16 amwell, it can calculate TRMS on anything between 20Hz and 1kHz, but it can measure frequencies up to60MHzaccording to the above datasheet. bear in mind that TRMS, if done digitally, requires a fair bit of oversampling to work.also of note, temperature can be measured with either k-type thermocouple or a resistive PT100 sensor.from the inside views, it looks like there is a 5-wire connector off the multimeter PCB running to the AC PSU and serial PCBs. an educated guess is that this carries a single-ended supply (2-wires) and opto-isolated serial (3-wires). if this is the case, modification for battery powered may well be on the cardscheers,rob :-)

author: indman
author_rank: Super Contributor
timestamp: March 16, 2021, 10:44:09 am
content: Quote from: Microcheap on March 16, 2021, 08:39:29 amThe 1kHz BW deprives this model of all advantages and equates it to the AN888S and similar low-cost devices.

author: paf
author_rank: Regular Contributor
timestamp: March 16, 2021, 11:40:38 am
content: The good things about this multimeter are the looks and the small size,But, an East Tester ET3240 can be had for 130 Euros in EU (Aliexpress but delivery from CZ!) and has 4 wire resistance measurements...Review:https://lygte-info.dk/review/DMMEastTester%20ET3240%20UK.htmlWhat do you think?

author: Fungus
author_rank: Super Contributor
timestamp: March 16, 2021, 12:01:24 pm
content: Quote from: paf on March 16, 2021, 11:40:38 amI think the East Tester ET3240 looks far too big for my bench and is ugly. ;-)

author: Fungus
author_rank: Super Contributor
timestamp: March 16, 2021, 12:08:33 pm
content: Quote from: coromonadalix on March 16, 2021, 09:34:16 amDon't you have an oscilloscope for that?High frequency multimeters were for back when oscilloscopes were really expensive and didn't do on-screen calculations. 1kHz will cover just about all AC measurements made with a multimeter these days.

author: indman
author_rank: Super Contributor
timestamp: March 16, 2021, 12:30:31 pm
content: Quote from: Fungus on March 16, 2021, 12:08:33 pmAnd why should I take out and turn on the oscilloscope if I can easy measure AC with a multimeter which has a bw of 10-100kHz?

author: Kleinstein
author_rank: Super Contributor
timestamp: March 16, 2021, 12:55:45 pm
content: 1 kHz BW limit for the TRMS mode is a bit low. However it depends on how sharp the limit is. A lower BW can also have the positive side of seeing less noise.For digital RMS one does not necessary need a lot of oversampling. Just some pseudo random sampling timing is enough and could even work with undersampling (e.g. 1 MHz BW with 100 kHz sampling).The BW limit may as well be due to the analog input part.The BW specs for the analog RMS chips are also a bit tricky: at lower amplitude the BW can go down and this can cause linearity errors. At some 5 or 10% of the fullscale (this may be a range one may have to chose for some signals) the BW may no longer be that large.It looks funny to have a maximum speed of some 65 readings per second - that is just a little faster than 1 PLC. So one would get only slightly higher speed at the price of no longer mains hum supression and possible aliasing that can cause confusion. I would normally consider the range of 51/61 SPS to some 250 SPS as relatively useless, as it is effected by mains hum, but can not really resolve it. If the meter does RMS the digital way, which is a reasonable decision, they should be able to do faster readings (e.g. 2 kSPS) too. Maybe they should switch from slow RS232 to USB.

author: rsjsouza
author_rank: Super Contributor
timestamp: March 16, 2021, 01:17:33 pm
content: Quote from: indman on March 16, 2021, 10:44:09 amI agree with you; the form factor is pretty interesting, but its price takes it to the level of very capable handhelds. It is a pass for me.

author: Fungus
author_rank: Super Contributor
timestamp: March 16, 2021, 02:05:29 pm
content: Quote from: rsjsouza on March 16, 2021, 01:17:33 pmI'd give it a pass, too. Definitely looks better than the Aneng bluetooth speaker thing.The probes look horrible but you can get awesome probes for $4 on Aliexpress, so... no biggie.

author: msquared
author_rank: Regular Contributor
timestamp: March 16, 2021, 09:59:07 pm
content: Got the dreaded ebay message today for my XDM1041 order:"I am writing here with all my sincereness to say sorry to you .I was just informed that your package are sending back due to the customs issue .Ebay suggest us to refund you all to protect your Consumer Rights in this condition ."Looks like I need to find a new seller. This one had over 172k in their feedback score, thought I was in good hands.

author: rsjsouza
author_rank: Super Contributor
timestamp: March 16, 2021, 11:37:12 pm
content: msquared, this is better than what the Aneng Official Store did to me: they said that shipped the order and it was in the courier's hands. Three months later they tried to stall my dispute by moving the processing dates and on its final days they said the package was located and returned to them due to a "customs issue". Obviously they offered to resend the package to avoid the bad review and the cancellation.

author: coromonadalix
author_rank: Super Contributor
timestamp: March 17, 2021, 05:53:13 am
content: I cancelled a purchaseDid not liked the seller bad purchases reviews / comments in the last month(s), tried the sellers with the most sales amounts .... with timed sales countdown and low quantities, that's a don't buy signal for me

author: m.p.h
author_rank: Newbie
timestamp: April 09, 2021, 11:22:32 am
content: Hi All!Does anyone have a user manual for the XDM1041?Looked almost everywhere, but even the DEU dealer "Messgeräte Chemnitz" has nothing availableHave a great day!Michael

author: msquared
author_rank: Regular Contributor
timestamp: April 09, 2021, 05:25:31 pm
content: I got mine yesterday. Here's a couple of quick observations and results from my initial playing around, I should have more time this weekend.If anyone wants any specifics let me know.First the bad:No real manual included, just a quick start guide.Display is slow to update when changing functions or modes (you can watch it clear screen like an old terminal)Not instant on, takes about 5 seconds to boot (Also you have to hold the power button for 2-3 seconds to power on)Would have been nice to have some flip out front feet to change the angleAuto range is slow, it takes a few seconds to "lock on". I noticed this on all functionsNow the good:Small with big display, fits on the bench nicelyDoesn't really tip over when pressing buttons, top buttons tend to make it tip a bit but buttons are fairly soft with a nice tactile feelContinuity is fast and configurable from 1-1k but not as fast below the 50default, buzzer is loud but not screamingAC voltage drops off sharply at 4K not the 1K in the specs at least @ 5V RMSMeter is accurate 5V using my DMMCheck comparing to readings on Keithly 2001 (Honestly to be expected, it's not that difficult to manufacture a decent 55k count meter today)As above for current, resistance, and capacitors

author: thoeffer
author_rank: Newbie
timestamp: April 13, 2021, 03:46:53 pm
content: I picked up the XDM2041 as I was looking for something that would sit on top of the Fluke 8840a.I know WHY did I get it if I had the FLUKE? CAPACITANCE Checker & Frequency counter. Thats it.It is a bit slow changing modes & autoranging. But it works well. I would have to spend a LOT moreto get a Meter with a Frequency Counter that goes as high or waste more bench space getting adedicated Counter. I'm just a hobbyist anyways not a REAL EE.I'll post pics later tonight.Ty HoefferPalmyra, VA

author: Oilngas
author_rank: Contributor
timestamp: April 14, 2021, 07:33:30 pm
content: I've been watching to see when these show up on Amazon. There's a couple there already but minus the Owon badging.https://www.amazon.com/Multimeter-Temperature-Instruments-Laboratories-Factories/dp/B08VNNYMTB/ref=sr_1_20?dchild=1&keywords=owon+xdm+bench+multimeter&qid=1618361813&sr=8-20https://www.amazon.com/dp/B08W221DGK/ref=sspa_dk_detail_2?psc=1&pd_rd_i=B08W221DGK&pd_rd_w=B6cKf&pf_rd_p=085568d9-3b13-4ac1-8ae4-24a26c00cb0c&pd_rd_wg=mm6UM&pf_rd_r=JSZZ256VX752Q993FRCR&pd_rd_r=878d572e-ea35-471c-a743-b92b23c05add&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFNTFMzNlJHMkRIOTEmZW5jcnlwdGVkSWQ9QTAxMjg1ODcxWE83RTc2UkVHSkxNJmVuY3J5cHRlZEFkSWQ9QTA3OTE4MTkxU1AwV0pFSjZITzBTJndpZGdldE5hbWU9c3BfZGV0YWlsJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

author: theHWcave
author_rank: Regular Contributor
timestamp: April 22, 2021, 09:55:01 pm
content: thanks msquared, I like the form factor because it would fit nicely on the shelf above my work table but I am slightly worried that the screen will burn in if left on for hours on end. Does it have a screen saver or something ?Any experience (good or bad) with data logging and the PC interface?

author: msquared
author_rank: Regular Contributor
timestamp: April 23, 2021, 04:29:52 am
content: I couldn't find any screensaver but it is possible to turn the back light up and down in 25% increments making the screen pretty dark but I don't know if that will really make any difference in screen life or burn-in.As far as the data logging goes... I tried the XDM2041 software but that was a no go. I was able to connect to the serial port (which is fully configurable from the UI with all the typical serial settings) and using the XMD2041 programming guide as a reference got it talking through putty in about a minute (there's no echo so you're typing blind). The command set is pretty easy, just basic SCPI so nothing to difficult. I don't think it's going to be much of a task to get it logging.The other slight annoyance I've had is it doesn't remember the previous settings, it always defaults to "slow" mode but for quick troubleshooting or a couple of measurements "fast" mode works much better for auto ranging.Overall still pretty happy with the little bench meter. I used to keep a Fluke 289 on the bench but know it's sitting on a shelf and the little meter has taken it's place.

author: Fungus
author_rank: Super Contributor
timestamp: April 23, 2021, 07:38:40 am
content: Quote from: theHWcave on April 22, 2021, 09:55:01 pmI don't think it will have an OLED screen at that price.

author: theHWcave
author_rank: Regular Contributor
timestamp: April 24, 2021, 09:45:35 am
content: many thanks for the update msquared, I am probably going to get one ... (not that I really need yet another multi-meter)

author: coromonadalix
author_rank: Super Contributor
timestamp: April 24, 2021, 10:51:36 am
content: Can we see the inside without breaking the warranty ??\Duh sorry

author: Oilngas
author_rank: Contributor
timestamp: April 24, 2021, 04:45:21 pm
content: "Can we see the inside without breaking the warranty ??"There is a picture of the inside in the first pdf attached in reply #20.

author: martinr33
author_rank: Frequent Contributor
timestamp: May 01, 2021, 02:28:02 am
content: Pics of the insides.https://photos.app.goo.gl/YB3sELWjAqYZQNGQ8

author: coromonadalix
author_rank: Super Contributor
timestamp: May 01, 2021, 07:34:35 am
content: hy3131 based dmm icsame as the eevblog 121gw ....

author: SpecialK
author_rank: Regular Contributor
timestamp: May 02, 2021, 03:29:56 am
content: Quote from: coromonadalix on March 10, 2021, 10:48:15 pmhttps://www.amazon.ca/dp/B08VNNYMTB/?coliid=I1CDLRHLC3DHDN&colid=3GVSYACE2F0LE&psc=1&ref_=lv_ov_lig_dp_it$164 CDN with a $15 coupon. I'm pretty tempted. I have an XDM3051,which other than having a fan that's a bit on the loud side, is pretty good,This looks like the same user interface.

author: pallav.aggarwal@gmail.com
author_rank: Contributor
timestamp: May 02, 2021, 07:07:05 pm
content: I have purchased this multimeter recently and quite happy with the performance so far. The main purpose was to use it in my test jig.I have also created a small video:https://youtu.be/rBGuiqlnOJM2nd video showing how to interface with SCPI commands:https://pallavaggarwal.in/owon-xdm1041-programmable-multimeter/Hope this will be useful for some people.

author: Oilngas
author_rank: Contributor
timestamp: May 02, 2021, 08:02:51 pm
content: Quote from: SpecialK on May 02, 2021, 03:29:56 amAs noted in my earlier post, "Owon" does not show up in the Amazon pictures or the description, just "XDM1041". Not sure if this is significant but it seems a little sketchy to me.

author: rsjsouza
author_rank: Super Contributor
timestamp: May 02, 2021, 10:43:08 pm
content: This is not uncommon. These DMMs usually have several OEMs and Amazon sellers sometimes test the waters with unknown brand names - I got a Sinerky UT136C (Uni-T UT136C), a no-name DM139C (Uni-T UT139C) and a single batch production Surpeer AV4 (HY-19 IIRC) - all at a significant price reduction at the time.

author: Kleinstein
author_rank: Super Contributor
timestamp: May 03, 2021, 07:25:31 am
content: That meter may show up under different names in the future. The OWON brand is nothing to be really proud off like a Fluke, HP or similar name.It looks like the meter does not show the brand name and so the seller did not add it, which is OK. If the seller would add the brand one could also get suspicious.The internals looks reasonable, with plenty of creapage distance as it should be. One point I don't like that much is that they use a SMPS and not a classic mains transformer. This may lead to extra common mode injected signal. The max. power at 15 W looks quite high. Even with just 15 VA and a relatively poor power factor it look high to me.It is nice that they have the RS232 part separate (looks like a max232 or similar on the small board). So there may be a easy way to change to the more logical direct USB.Chances are the RS232 version is some 20 cents cheaper.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: May 09, 2021, 05:13:43 pm
content: First:Tnx for posting pictures of the internals.I found this thread after first seeing it announced (from 2021-05-13) in a local shop:https://www.eleshop.nl/owon-xdm1041-multimeter.htmland then I started looking for more info, and found this thread.I have been looking for a decent Benchtop DMM (Big display, fits on shelf, PC connectivity Push buttons instead of rotary selector etc.) for quite some time.I do not have room for a 30cm deep meter though, and that is the reason I did not buy a Siglent 3045. The Siglent is also too slow for me in autoranging and connectivity test.Somewhat slow autoranging is accepable for a low power battery operated instrument, but it's inexcusable for a benchtop instrument.After I found out this uses the HY3131 I've been looking into that chipset a bit and it's quite popular for handheld meters:EEVblog 121GW. (EUR200 meter)Keysight 1280. ( EUR 600 meter)HoldPeak HP770D ( EUR 50 meter)Digilent DMM shield (EUR90) (No display, but Isolated interface)Eleshop announces it (localy in EU) for EUR 130 and this is definitely in my price range, and I like the form factor, push buttons and big TFT.I'm curious how far this HY3131 chipset can be pushed. Ideally it would be programmed to do some auto-sensing, and switches to a quick mode for auto-ranging, and to an accurate mode for more digits.There is a EEVblog thread about reverse-engineering and alternate firmware for a Fnirsi scope. I do not understand that effort. After looking into it the frontend of the fnirsi scope is simply not good enough to make something decent out of it (Quite a shame, it could be a very decent thing for a BOM of EUR10 more...)This XDM1041 looks extremely hackable though. The HY3131 complete with all measuring stuff and isolated interface is on a separate PCB from the "brains" part.The whole microcontroller board can be easily replaced by your favourite, and then you can write any software you want for it, and if you stay with STM32 then once firmware development has surpassed what Owon does you can flash it into the on-board GD32F303.I do not understand why Dave is complaining about why a benchtop DMM does not run on batteries. It seems a bit silly to me.But if you must...I find the Glue on SMPS module hilarious. It is also very easy to replace it with any power module you would like, including a battery pack, and I guess there is plenty of room left in the compact housing to add some decent batteries.Another hackable upgrade for this scope would be to add a uSD or dataflash chip for datalogging. Should not be too difficult.I do not give much for CAT ratings, I thing they're much overrated (for home or benchtop use). I'd rather have 50ct fuses then EUR10 fuses!This XDM1041 has some decent sized fuses, widely spaced components and even some well placed isolation slots.Overall, I'm not sure which path to follow.Almost all decent benchtop meters are simply too big for me. I do not like the rotary buttons of the (cheaper) benchtop UNI-T meters, nor the simplistic LCD of the more expensive UNI-T, and others with fluorescent displays are also not for this generation anymore. Simply can't compete with a TFT.I am looking forward to an in depth review of this meter. Especially auto ranging speed and the speed (and quality) of the continuity tester.Another point that is a real deal breaker for me is a peep function that warns if the probe is in a current banana bus, while voltage measurement is selected. That is just a too simple mistake to make, and it either destroys your meter, or it destroys both a EUR10 fuse and your probe tips. Just happened too many times for me.

author: SpecialK
author_rank: Regular Contributor
timestamp: May 09, 2021, 06:29:45 pm
content: A couple days ago the Amazon link I posted went down to $148 CAD minus a $15 coupon. I was very tempted even though I don't need it.Now it's $218 minus $15. To be fair, the Siglent 4.5 digit is like $500 and the 5.5 digit over $600. There's very little to choose from in bench DMMs at hobbyist prices. I think this should be a popular meter.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 09, 2021, 07:01:50 pm
content: Seeing other meters based on the hy3131 surely getting faster auto ranging should / could be possible ?For a battery pack, you have the battery bank for cell phones who could do a very good job, i have one based on 18650 cells that could be called a 25000 ma model lollI think it could snug in there or behind it ??Yeah the smps psu was fun to see in there

author: martinr33
author_rank: Frequent Contributor
timestamp: May 10, 2021, 04:54:35 am
content: The original photos of the innards (on the brochure) show a power supply integrated with the PCB.So we are looking at some kind of fix here. Esecially with the corner rounding and cutoff on the board - that's a reworked board from another design.https://photos.app.goo.gl/oj4yj544yRkzSndb6

author: rsjsouza
author_rank: Super Contributor
timestamp: May 10, 2021, 09:28:07 am
content: Wow, that's an ugly fix! It seems rushed and desperate to put product out.

author: theHWcave
author_rank: Regular Contributor
timestamp: May 17, 2021, 11:00:22 pm
content: I just got mine thru Ebay, straight from China to the UK, took about 2 weeks although the seller said 4 weeks.Interestingly, my power supply is exactly like in the brochure, no ugly fixbut they cheated on the fuses, instead of 2 decent 30 mm long high rupture ceramic as in the brochure, I got cheap 20mm long ones rated for 250V only, at least the 10A is ceramic.Other than the slowness already mentioned, the meter is quite ok for what it is. After a weekend of intense testing my summary is:the negatives:Capacitance above 500uF, auto range is not always working and one has to do manual ranging... capacitance is definitely the weakest mode anyway, the lowest range is just 50nF and 500pF or less shows only zeroRanging in volt mode is weird: it can auto range from the millivolt up to volts but not down from volts to millivolts. Same with manual ranging. To go from volts to millivolts or back you can't use the range up down, instead you have to select between volt and mV mode. You can get used to i, but interestingly this is just a problem of the user interface. The behaviour over SCPI is much more sensible, you can just go up and down using the RANGE command or use the CONF command without any issue.Rel mode is actually a maths function which means you can't have rel active and do averaging or dB/dBm at the same time since only one function can be active at a timeNo smart data hold which would have been easy in software..., just a silly run/stop button which is like a dumb holdon the plus side:I really like the temperature mode. Very comprehensive and can do PT100 or K-typeThe SCPI interface (RS-232) has its quirks, syntax wise, but once figured out, it works well and can deliver more decimals than shown on the display. Using that the accuracy is pretty good.The display is easy on the eyes, especially if those eyes are not as young anymore...It fits exactly under the first tier of the shelf at the back of my bench. That space is very shallow and very low, which is why I got this meter for it. It does not take any extra space on the work area, its mains powered and can be on the whole day, and its display is exactly at the right angle .And if you have not guessed it... the meter is always on as long as it's plugged into mains.The power switch on the front is only a soft-switch, but I measured the "standby" current to be only about 1mA at 230V, so its not too much of an issue.

author: coromonadalix
author_rank: Super Contributor
timestamp: May 18, 2021, 12:02:26 am
content: would be nice if Owon could read this thread and improve the meter in a fw update ??

author: msquared
author_rank: Regular Contributor
timestamp: June 02, 2021, 08:25:31 pm
content: It's finally official.https://www.owon.com.hk/products_owon_4_1%7C2_digits_xdm1041_bench-type_digital_multimeterAlso looks like there's already a newer version with a USB data port instead of RS232.So much for being an early adopter. Maybe time for a little internal USB mod...

author: theHWcave
author_rank: Regular Contributor
timestamp: June 02, 2021, 11:00:22 pm
content: I have this meter and I would strongly advise caution in trusting anything that's written on that Owon Hongkong page. Notice how they dither between USB or RS-232? They avoid making a clear statement. Of course nobody these days has RS-232 on a PC/laptop so we all use USB to RS-232 converters to talk to the meter using USB. And he presto, now your marketing people claim you "can" talk to the meter over USB! Of course you doCould you easily add USB, yes and no. No, if you mean a fully capable USB interface that is supported by the processor to for example mount and use USB sticks that you may plug in. The reason is that there are only 3 signal wires (tx,rx,gnd) that go from the digital board to the interface board and these are already RS-232 on TTL level. All the interface board does is convert these to RS-232 levels. It would need a relative large revision to change the hardware and firmware to do proper USB. Maybe they will do it eventually but I would not hold my breath. But if you want to replace the DB9 with a USB socket, nothing stops you from removing the level converter chip and replacing it with one of the standard USB-to-serial chips (usually some chip from Prolific or clone) that are normally embedded in the ubiquitous adaptor cables. That gives you a physical USB port for the marketing people but that "USB" would not give you any more capabilities than what you get now with a cable converter, i.e. a simple COMx or ttyUSBx interface.The greatest humbug IMHO is the record function. Absolutely useless! Yes the meter can record up to 1000 entries manual or automatically but there is no way to download them. I tried all kinds of methods. And don't be fooled by the Owon PC software. In desperation, I finally gave in and went through the pain of installing it. I also rigged up a complex setup with my scope to sniff and protocol-analyse the exchanges between the OWON PC software and the XDM1041 to finally learn the secret how they access and download the recorded data over the serial interface. Turns out they don't. What they do instead is make a new recording (reading new measurements via SCPI and storing them in a text file on the PC). I think there is simply no way accessing remotely whatever you may have already recorded on the meter. Even more expensive OWON meters have nothing of that sort in their SCPI implementation. I think in those meters you can dump the recording on a USB-stick but that would require a "proper" USB interface and that (see above...)

author: rdl
author_rank: Super Contributor
timestamp: June 03, 2021, 01:31:34 am
content: What is the point of the big "Trigger" annunciation on the display? The little square next to it seems to blink in sync with display updates, but that seems pretty useless to me.

author: theHWcave
author_rank: Regular Contributor
timestamp: June 03, 2021, 06:16:35 pm
content: Yes, in the XDM1041 its only purpose is to show that the display is updated ... There is no setting or anything to influence trigger apart from the "run/stop" button but that is a simple hold (no auto-hold or anything fancy)

author: coromonadalix
author_rank: Super Contributor
timestamp: June 04, 2021, 12:04:16 am
content: Would it be better to call it something like a "gate", or "measurement in progress" which could take too much space on the screen ...

author: davebb
author_rank: Frequent Contributor
timestamp: June 05, 2021, 05:30:30 pm
content: Quote from: theHWcave on June 03, 2021, 06:16:35 pmHi Great Youtube videosit was me with the temp problem with my meter, as i said when the meter is cold the temperature Reading is very goodafter about 10-20mins of the meter being on the reading reads 4-5d/c higher, what does your meter read with the k typedisconnected ?can you please tell me is there a temp reference in the meter and what does it use to do this, or is the reference in side the meter HY3131 chip, i have re soldered the chip but this did not help,also i took a photo of the ch 340 usb board that is fitted to mine, you can use it in your vids if you want to,Thanks for your help ,Dave 2E0DMB

author: Kleinstein
author_rank: Super Contributor
timestamp: June 05, 2021, 06:51:56 pm
content: The type K sensor is a thermocouple and it thus makes no realy sense to look at the reading, when open circuit. This would be effekted by the input bias and the relatively high input impedance (likely 10 M or even higher).It make sense to look at the reading with shorted inputs. This should read the internal temperature used for the cold junction. Dave has a relatively recent video on this.

author: davebb
author_rank: Frequent Contributor
timestamp: June 05, 2021, 07:09:24 pm
content: Hi Thanks for the info, is the internal temperature used for the cold junction in the HY3131 chip or is it external to the chip,Thanks i am trying to find out what is going on as i do not rely want to send it back to china as the meter is working well apart from this problem ,ThanksDave

author: Kleinstein
author_rank: Super Contributor
timestamp: June 05, 2021, 08:44:04 pm
content: Connecting a type K thermocouple just to the banana plugs is always tricky, as the banana plugs are usually copper / brass or similar. So the cold junction would be somewhere out at the connector. So it really depends on how the connections are made and it could be just a poor probe quality. The test with just a copper short would be more reliable than with a real probe. Some banana cable are also not that great and could cause a few µV of offset if one connector gets warm.Chances are there is some sensor near the COM terminal (due to isolation requirements it would be hard to measure at the other connector).One could test this by using a short with a copper cable and than warm up the COM connector (e.g. touch / warm with the hand). The closer the sensor to the terminal, the faster it can react.For an accurate reading a PT1000 or NTC temperature probe would be better. Thermocouple with just 4 mm connectors is more like a crude relative estimate with some extra uncertainty.P.s. : The linked teardown pictures don't show an extra sensor near the connector. So likely the HY3131 internal temperature only - ideally with some offset in software.

author: davebb
author_rank: Frequent Contributor
timestamp: June 05, 2021, 09:27:07 pm
content: Hi Thanks for all that info, i have shorted out the input and yes temp reading is good but after about the same amount of time the temp goes up high about the same amount, just like it does with a probe, There is a relay in line in the circuit, so the next thing to try is to link it out to see if it is that,Thanks Dave

author: Kleinstein
author_rank: Super Contributor
timestamp: June 05, 2021, 10:25:18 pm
content: I don't expect the relay to be the problem. Chances are the relay is a latching type and not getting really hot.The more likely problem is that the whole meter gets warmer with time. With a copper short the meter should show the temperature of the connector(s). So some rise above the room temperature is correct. There is still a chance that the correction for the meter getting warmer is not correct (e.g. to much, as the chip likely heats up more than the connector).With no sensor at the connector the meter can not reliably get that temperature - the cables can have quite some effect on the temperature at the connectors. So one can not expect a really good conpensation of the cold junction.Besides the problem inside the meter, it is also the question where the actual cold junction is. Ideally it would be on the inside of the terminals, like the TC wire going all the way to the tip if the plugs or plugs made from thermocouple equivalent material. The more likely construction is having normal cheap plugs made from brass and thus a cold junction a bit outside. This could add some error, though likely less than 50% of the cold junction variations. So I don't hink the probe could explain a similator effect as with the short.Is the thermocoule at least reading external temperature changes about right (e.g. some hot/cold water) ?

author: davebb
author_rank: Frequent Contributor
timestamp: June 05, 2021, 10:34:31 pm
content: Hi yes it reads fine until about 10-20 mins and it follows another meter until it has been on for this time,Thanks Dave

author: theHWcave
author_rank: Regular Contributor
timestamp: June 05, 2021, 10:44:44 pm
content: @Kleinstein: I examined the board carefully and I don't think there is another sensor. I think they rely on the HY3131.I recorded the displayed temperature with shortened probes when the meter is turned on after being off overnight. Over 1 hour it climbed from 18.9 to 27 degC. But not smoothly. There were very distinct steps. This could be something else interfering as I was not paying attention, so I will repeat that again. Right now it shows 26.9 with probes shortened. With a K-type probe (borrowed from a BM235) it shows 27.7 The BM869S with a pretty good (=expensive) K-type probe shows 26.9 at the same location.I will do some more testing tomorrow

author: davebb
author_rank: Frequent Contributor
timestamp: June 05, 2021, 10:49:28 pm
content: Hi Thanksif you could run some more tests that would be good,Thanks Dave

author: wizard69
author_rank: Super Contributor
timestamp: June 06, 2021, 12:56:08 am
content: Thermocouple could junction compensation needs to happen as close to the cold junctions as is possible. Doing so on the PCB might result in a significant error.The first thing that should be done is to determine where the cold junction sensor is. As has been explained that should be relatively close to the banana jacks, if not it is a design fail.Quote from: theHWcave on June 05, 2021, 10:44:44 pmThis shift is excessive and could indicate a part failure or simply the cold junction sensor being it the wrong place. I'm thinking hard here but if the cold junction sensor was heating up then I'm thinking the displayed temperature should be going down. Generally the offset associated with the cold junction is subtracted from the millivolt value at the measurement point.A short, zero millivolts, represents 0ºC for a K-type thermcouple. You would then subtract the reference junction voltage but here is the problem, you don't have another junction in an all copper connection scheme. It would be interesting to see the behavior of the meter with a K type TC at the ice point. This would create the second junction to be compensated at the meter terminals.If you have a room temperature of 20 degrees a shorted input should result in an approximate negative 20 reading. This if there is no second junction to offset the reading. In any event my mind is a big foggy here and I worked extensively with type T TC's in the past where the copper conductor eliminated one joint requiring compensation. My point is that reading room temperature might not make sense with a short.QuoteOne thing to consider is air flow. IF this is indeed a reference junction compensation problem cooling the unit down after it heats up should result in fairly fast response on screen.In any event I may need to think more on this. I'm not at work at the moment so I can't set up anything to test the idea expressed above.

author: wizard69
author_rank: Super Contributor
timestamp: June 06, 2021, 01:12:01 am
content: As a follow up to the above post I remembered that my new EEVBlog meter does K type thermocouples and it indeed reads room temperature with the test lead shorted. This is causing me a bit of confusion as it implies that they are adding the reference junction temperature to the reading.It is getting late so I may end up sleeping on this. As I've said it has been awhile since I was heavily involved in TC work and that was mostly with type T. In this case though both TC are in very similar millivolt ranges at room temperatures.in any event drift is the problem here.

author: Kleinstein
author_rank: Super Contributor
timestamp: June 06, 2021, 06:00:13 am
content: The thermocouple probe gives 0 V if the TC tip is at the same temperature as the cold junction. So the cold junction temperature is added, not subtracted. The type K TC constant is relatively constant, so one can assume adding the temperatures. It actually is adding the calculated voltage to take into account a possible nonlinear TC response. Here the simple approximation of a constant thermopower should be OK.So a copper short reads the cold junction temperature used by the meter.The cold junction sensor away from the actual terminals is a weakness in the design, but with the normal banana plugs it is anyway difficult to get an accurate measurement. There is a good reason the for accurate TC readings they use special connectors.Measuring the temperature at the volts input terminal would be very tricky with isolation.The readings of 26.9 - 27.7 °C for the different probes and with 2 meters are not that bad. With the current warm weather and some self heating from the meter this sounds reasonable. Melting ice can be used as a reasonable reference temperature. The other simple test point is boiling water.With the standard plugs one has to accept a few degree of uncertainty. TC probes are not made for high absolute accuracy and the 4 mm plugs and CAT rating of the meters add another complication. The initial reading can be off, as the meter may need to warm up before getting good readings. With the sensor at the main chip this would be normal. With turbulent air flow there can be some temperature variations at the chip. The heat up curve can be a bit more complicated than just a simple smooth exponential and the temperature reading my not be very frequent.

author: theHWcave
author_rank: Regular Contributor
timestamp: June 06, 2021, 01:39:42 pm
content: The OWON XDM1041 temperature weirdnessI did a few measurements this morning and here are the results. Note that all this about firmware version 1.2. The graphs were taken by polling the measured value via SCPI every second into a spreadsheet.From the cold-start and warmed-up graph you can see that the meter looks at the internal temperature sensor every 600 seconds (10 minutes). During that time (about 3 seconds) the meter does not respond to SCPI polls, i.e. 3 polls time out but at the 4th one you get 4 results (i.e. it buffered the responses internally). Note that this “pause” on SCPI every 600 seconds only happens if you are in temperature mode. If you are in millivolts for example there is no pause.Interestingly, the very first temperature measurement after it updated the value it holds as cold-junction temperature is always a bit high. Not sure why. This you can clearly see in the warmed-up graph.In temperature mode, the meter displays the “measured” value at the bottom of the display (what a brilliant idea! Seriously why don’t other meters copy that). This allows an easy check if it is “doing the right thing”.Example: With just cables to my millivolt source plugged in, but no external voltage applied, it reads 28 deg. and -0.02 mV Using the NIST tables / polynomials for K-type, 28 deg. corresponds to 1.122 mV. This it stores as the cold junction offset (for the next 10 minutes).If I now apply +1 mV to the input, the meter shows 52.7 deg.C and 0.98 mV. The meter adds the 0.98 to the stored 1.122mV and gets 2.102 mV. According to the NIST polynomial equation that would be 51.9 deg.C. Ok so its off by 0.8 deg. Maybe they use lookup tables instead of the reasonably complex maths.If I apply -1 mV to the input, the meter shows 2.8 deg. C and -1.03mV. Doing the same calculation, the resulting voltage is 0.092mV and the NIST value 2.3 deg C. Again, 0.5 deg. off but I think in principle the meter is doing the right thing.@davebb: If your meter shows the right value at startup but not some time afterwards, it seems it may not do its 600s refresh of the cold-junction temperature. The best way to find out is to repeat the same test I have done for the cold-start graph and see if you get that staircase (or the spikes in the warmed-up) graph. You could use the OWON software and its recording function but I am not sure how it responds to the “pause” after 10mins. Better to use a small script and simply send every second: “MEAS1?<LF> “ and store the response

author: theHWcave
author_rank: Regular Contributor
timestamp: June 06, 2021, 03:17:47 pm
content: @davebb: coming to think of it. An easier way to check if the cold junction temperature is properly updated is to start the meter after it was off and cold with shortened probes and wait. Over 30-60 minutes, the temperature reading should increase (by several degrees) as it heats up internally.

author: Kleinstein
author_rank: Super Contributor
timestamp: June 06, 2021, 03:37:22 pm
content: The rather slow update of the cold junction temperature is a bit anoying. So one has to essentially wait at least some 30 minutes for warm up.In addition there seem to be a few point's that are off just after a update.I wonder if one could force an update by switching between a mV rading and a temperature reading. If the meter does not measure the temperature in mV range it may do an internal temperature reading just after changing the function. At least with program control one could this way force the internal reading more often if needed.

author: theHWcave
author_rank: Regular Contributor
timestamp: June 06, 2021, 03:53:34 pm
content: A very good point and I tested that just now. Sadly the 10 minutes cycle to refresh the cold junction temperature reference seems to run independent of what mode you are in

author: davebb
author_rank: Frequent Contributor
timestamp: June 06, 2021, 04:21:40 pm
content: Hi I have had my meter on for some time, it is reading 32.5c with input shorted , real temp in the room is 25ci am now going to switch the meter of to cool down and then run a test with the easy dmm software recordingbut it does look as this part of the meter is duff,Thanks Dave

author: Kleinstein
author_rank: Super Contributor
timestamp: June 06, 2021, 04:56:31 pm
content: The part around the connects would warm up somewhat. So 6 degree higher than room temperature may be actually right.Even with a seprate sensor near the ground therminal there is still the problem if the other terminal is the same temperature. From the design good TC probes would have to have low thermal conductivity to the outside, so that the assuption of a temperature relatively close to the meter internal temperature is not that bad.

author: davebb
author_rank: Frequent Contributor
timestamp: June 06, 2021, 05:07:53 pm
content: HiI do not think it is correct , it reads correct when cold, and with the probe it reads correct until it jumps after about 10-20 mins , i will log when it has been off for some time,I will post the log soon,Thanks Dave

author: davebb
author_rank: Frequent Contributor
timestamp: June 06, 2021, 06:15:49 pm
content: Quote from: theHWcave on June 06, 2021, 01:39:42 pmMy be they messed mine up with firmware version 1.3.0 that mine has ?Dave

author: davebb
author_rank: Frequent Contributor
timestamp: June 06, 2021, 07:36:29 pm
content: Hi i have attached the log of the meter of the internal reading front ports shorted at the meter,Thanks Dave

author: theHWcave
author_rank: Regular Contributor
timestamp: June 06, 2021, 07:52:22 pm
content: @Kleinstein: The only temp. sensor is the one inside the HY3131. Its physically a fair bit away from the probe sockets and not thermally connected other than through quite a bit of PCB material and ambient air inside the meter. That said, I stuffed an external k-type sensor into one of the sockets and measured the temperature which is within 0.5 deg. the value cold junction temp shown by the meter. I guess that is kind of acceptable (given the price etc)

author: theHWcave
author_rank: Regular Contributor
timestamp: June 06, 2021, 08:07:48 pm
content: @davebbwhat a terrible format that OWON PC software produces....Besides that, the good news is that your meter behaves exactly like mine. Every 10 minutes the cold junction is updated.18:47 25.618:57 jump to 29.719:07 jump to 31.2So that part works as expected and the firmware did not do anything bad (or good)Now with that established and the meter in a warmed-up state can you give:1. the temp reading and the measure value shown on the display with probes shortenedthen replace probes with K-type (the right way around ! and take care not to touch close to the tip)2. he temp reading and the measure value shown on the display with the k-type in and what value it should be (according to some other thermometer you have)Thanks

author: davebb
author_rank: Frequent Contributor
timestamp: June 06, 2021, 08:48:17 pm
content: HiThe meter has been on for some time withe the input shorted it reads 33.4c 000.02mv, and 25.4 on another thermometerwith a k type it reads 34.6c 000.07mv, and 25.5 on another thermometer ,When the meter is on from cold i had a reading with in 0.5deg c betwen meter with probe and thermometerThanks Dave

author: theHWcave
author_rank: Regular Contributor
timestamp: June 06, 2021, 10:00:23 pm
content: Very strange! These values seem correct. That is, if the socket temperature (cold junction) is indeed 33.4 deg.C and the measured value with K-type is indeed 0.07mV then the readout should be 34.6 deg C. To see 25.5 in this situation, the measured value should have been -0.301 mV. Are you sure this thermocouple is working and is a k-type? Also what are you using to plug it into the meter? Can you send a photo of the way the couple is plugged in?Thanks

author: davebb
author_rank: Frequent Contributor
timestamp: June 06, 2021, 10:19:30 pm
content: Hi i am using a k type with 4mm plugs from another owon OW18E handheld and the same with another one from another meter and with that meter is reads slightly lower then my room thermometer, if voltage reading is correct why does the internal temp in chip reading go so high as well after 10mins, did they use the wrong calibration settings at owon, and both read correct when the meter is cold ,Thanks Dave

author: davebb
author_rank: Frequent Contributor
timestamp: June 06, 2021, 10:38:05 pm
content: To test the internal chip sensor i used 2 good 4MM plugs and the copper core from some rg213 coax cable between the to plugs so is very short,The meter has been running a long time now and is reading 35.2 with the k type , and 33.4 c with the short,the room temp is 25.5cThanks Dave

author: Kleinstein
author_rank: Super Contributor
timestamp: June 07, 2021, 06:16:48 am
content: The socket inside the meter should get warm. So the 33.4 C for the short are plausible. The strange thing is the low voltage measured for the thermocouple. So it the the thermocouple working, e.g. showing about the right difference for something like boiling hot water or ice water.The numbers shown would point to a failure with the probe or maybe the 50 mV voltage range. Chances are the temperature measuremetn would use the 50 mV voltage range. So one could do a test with a more or less stable voltage in the 20-40 mV range and measure this in both the 50 mV and 500 mV range.

author: davebb
author_rank: Frequent Contributor
timestamp: June 07, 2021, 06:45:57 pm
content: Hi thanks for the info yes the k type is working, it does not jump temp on any other meter i have tested with other k types and get the same problem,i have now tested with 30.842mv from a psu and when i ended the test it was 30.927mv showing at the end of the log file When i switch over to voltage,and that was correct with another meter,Thanks all for your HelpThanks Dave Browne 2E0DMB

author: theHWcave
author_rank: Regular Contributor
timestamp: June 07, 2021, 09:00:37 pm
content: I am using a K-type that came with the BM235. It has 2x 4mm banana plugs on one side and the K-wire pair comes directly out of the other end. For my BM869S I use a specially made adapter that has 4mm banana plugs on one side and a small 2-pin socket especially for thermocouples on the other side. My RS-component K-type thermocouples I bought for this meter end in those plugs that fit the sockets in the adaptor.In both cases the cold-junction (i.e. the non-sensor end of the K-type wires) actually happens outside the meter. Depending how “hot” the XDM1041 terminals are and how well the banana plugs conduct that heat, the cold-junction may be quite a bit lower in temperature than what the XDM1041 thinks it is. In handheld meters this seems to be less of a problem because they are seldom on for long periods and generally more power optimised. This means the inside temperature of a handheld is closer to ambient.This could well be the problem of your meter which seems to run hotter than mine. I have never seen more than 28 deg after hours of operation but you seem to run at 31 or so. It shows correct for the first couple of 10-minute cycles until it adjusts the cold-junction to 31 deg which is way higher than the real ambient temp.The first question is why does it get hot inside? The power supply is always on, regardless of the power switch so that is not it. The HY3131 with the actual temp. sensor consumes max 0.5W and the processor even less. In the end I had to open the meter and examine it with a crude self-made thermal imaging camera (MLX90640 sensor & Raspberry Pi). The only thing that gets quite hot is a 1 ohm SMD resistor next to the LCD connector. When I turned the backlight to the lowest setting, the heat disappeared.So here is a test you can do. Run the meter at the lowest backlight intensity and check if you getting better accuracy. I have done this now for 30 mins and the temperature has dropped by 2 deg.Although I think mine is generally ok as long as I use the BM235 probe which probably gets warmed quickly through the sockets, I am seriously thinking of opening some of the “vents” at the back with a drill. They seem to be more style than function.

author: davebb
author_rank: Frequent Contributor
timestamp: June 07, 2021, 09:16:36 pm
content: Hiok i will try lowering the back light and see if that helpsbut i did run the meter open and it did not make much difference,Thanks for your helpDave

author: davebb
author_rank: Frequent Contributor
timestamp: June 07, 2021, 10:37:02 pm
content: Hi yes you are correct it has changed the temp by about 2 dg/c by turning the screen brightens to 0, and i have moved the meter in to free space only reading about 2.5dg/c high now,Please let me know if you find anything more,Thanks for your HelpDave

author: Misk
author_rank: Newbie
timestamp: June 09, 2021, 08:07:46 pm
content: Sorry for my english. I buy OWON XDM1041 and I have a problem with it. Problem in this videohttps://www.youtube.com/watch?v=rcfSdUYxkVM.The measuring of megaoms resistors is bad and unstable. I think the HY3131 is bad. Can anyone measuring the 10MOm resistor on a analog board of XDM1041 near the HY3131 (conected to 5 pin from end). I measuring 8 MOm and the risistance change, when I repositing my body and other objects. When I touch the board it change to 6MOm. The resistor 10Mom is good. I test them separetly. I need to know, how the good HY3131 work.The return of the device is expensive for me. Other function work satisfactorily for me.

author: Kleinstein
author_rank: Super Contributor
timestamp: June 09, 2021, 10:21:08 pm
content: The resistor reading seems to change with the meter taken of the ground. This could indicate something like a problem with EMI or maybe too much mains hum.

author: davebb
author_rank: Frequent Contributor
timestamp: June 09, 2021, 10:30:19 pm
content: Hi Have you tried a PT100 to see if that works ok, does the meter still use the same temp in the HY3131 for 10min calThanks Dave

author: theHWcave
author_rank: Regular Contributor
timestamp: June 09, 2021, 11:08:15 pm
content: The meter was running the whole day today using the BM235 K-type probe with its sensor next to a PT100 which was connected to the 34401A. I recorded the values from both every 30s over almost 10 hours. The XDM1041 was consistently about 1.8 deg. too low but followed the temperature variations exactly. This was using the lowest backlight. When I plugged the same K-type into the BM869S (without changing anything else) it showed about 1 deg lower that the 34401A's PT100 reading. So I would say 1 deg error due to the K-type probe itself (totally expected) and 1 deg due to the XDM1041 thinking the ambient temp. is higher than it is. Although backlight is low, some things still produce a little heat and it builds up because there is very little airflow. Next step (weekend probably) is to widen the cooling vents in the DDM1041 and see if I can get the internal temperature lower.The PT100 is another story. I have a proper 3-wire one from RS-Components so reasonable quality. Not sure if you are familiar with 3-wire PT100 but basically you need to eliminate the resistance of the wires to the sensor head. PT100 is using resistance and 100 Ohm = 0 deg. C. The change in resistance is very little from 100 to 110 Ohm is the equivalent of 0 deg C to over 25.5 deg C so you can see that milliohms count here. There are special circuits for 3-wire probes but I am using the fact that 2 wires are connected at the probe end. So if you use these and measure the resistance you get a value of 2x the resistance of the length of the probe cable. I use that to null the meter and then replace one of the wires at the meter with the 3rd one (that goes through the probe). And this is where the XDM1041 fails. You can null the PT100 probe in resistance mode, no problem. But when you go to Temperature mode and select PT100 it ignores the REL value for resistance and shows the value that includes the wire resistance. REL in Temperature mode nulls the temperature value not the resistance. Using PT100 on a XDM1041 iin temperature mode is useless unless you use an extremely short or very thick cable to the sensor head. I mean that is doable but why? The alternative is to use the PT100 in resistance mode (with proper null of cable resistance) and convert the resistance to temperature by hand (or script when reading from SCPI). This is by the way exactly what I have done for the 34401A because the 34401A has no PT100 mode so I am simply reading the resistance and convert that using the PT100 formula as long as you go only positive (> 0 deg C) its not too complicated.# convert ohm to deg.C using PT100 probedef PT100(ohm):TC = 0.00385A = 3.9083E-03B = 5.775E-07R0 = 100.0return (-A + math.sqrt(A*A - 4*B*(1-ohm/R0)))/(2*B)Does it do the 10 minute - cold-junction update in PT100 mode? I have not tested it but I am almost sure it doesn't. I mean it may still do it in the background but since PT100 does not need the ambient temperature it should not show. But I will test it tomorrow and report

author: theHWcave
author_rank: Regular Contributor
timestamp: June 09, 2021, 11:16:29 pm
content: @MiskFor anything above 100K or so, you must use LOW speed. Secondly AUTO RANGE is not reliable at high resistance values. Try manual range. Using this I can measure 10 Meg with good accuracyIt is very similar to capacity mode. I find that > 1000uF you have to use manual range or you never get a good reading.

author: Kleinstein
author_rank: Super Contributor
timestamp: June 10, 2021, 05:11:10 am
content: Pt100 is problematic with 2 wires. 3 wire mode is usually not supportedd by DMMs. Bendch DMMs usually support 4 wire mode - though it looks like the XDM1041 does not. With 2 wire connections it would be better to use Pt1000 instead of Pt100.The accuracy of thermocouples is often nor very good, but the error is usually more like a percentage of difference to the room temperatur. At essentially the room temperature there is not much error from the TC itself. There can be some error from the connectors, from lokal temperature gradients. It is more the PT100 sensor that can have an offset-error.

author: Misk
author_rank: Newbie
timestamp: June 10, 2021, 06:13:32 pm
content: Quote from: theHWcave on June 09, 2021, 11:16:29 pmThank you. I ask OWON support one week. Finally I get a special firmware from OWON and the all problems are solved.

author: davebb
author_rank: Frequent Contributor
timestamp: June 10, 2021, 07:01:24 pm
content: Quote from: Misk on June 10, 2021, 06:13:32 pmHi do you up load the firmware with the rs232 / usb port,Can you please post the new firmware and is there a loader program , Thanks Dave

author: davebb
author_rank: Frequent Contributor
timestamp: June 10, 2021, 07:26:41 pm
content: Hi MiskHave you tested with a K-type probe to test the Temp,if you have does yours read ok ?, do you get a jump in temp after its been on for 10 mins?what version firmware are you now usingThanks Dave

author: theHWcave
author_rank: Regular Contributor
timestamp: June 10, 2021, 08:45:28 pm
content: Quote from: Kleinstein on June 10, 2021, 05:11:10 amTotally agree with that, although you can use 3-wire as I described in my previous post with REL to null the wire resistance. Unfortunately the XDM1041 ignores the REL value for Ohms when using the PT100. With PT100 the error caused by wire resistance can be significant. My probe has 0.262 Ohm (2-way) wire resistance. Without REL, this adds to the resistance of the sensor. At 5 deg C, that causes an error of 13%, at 10 deg.C still 6.5%, 20 deg.C 3.3%. Only for >70 deg.C will the error be 1% or less. So for high temperature measurements, the PT100 is usable in the XDM1041, for room temperature sadly not (unless you change the sensor wires to have very little resistance).

author: theHWcave
author_rank: Regular Contributor
timestamp: June 10, 2021, 08:48:23 pm
content: Quote from: davebb on June 09, 2021, 10:30:19 pmI tested this today and as expected, there is no 10min cal cycle in PT100 mode

author: davebb
author_rank: Frequent Contributor
timestamp: June 10, 2021, 08:53:22 pm
content: ok thanksit would be good to know what this new firmware that misk has now got and if it still does this,Thanks Dave

author: theHWcave
author_rank: Regular Contributor
timestamp: June 13, 2021, 09:32:23 am
content: Yeah, same here. After I saw Misk's post, I send an email to OWON asking about it.... but no response (so far). I'll post if I hear anythingI did an interesting test yesterday using a Peltier element cooling an old heat sink = chunk of aluminium. I had a PT100, the unknown K-type I normally use for the XDM1041 and a known (RS-components) K-type which I use for my BM869S all attached to the same area on that heat sink. Long story short, it seems as if the XDM1041 was much closer tracking the PT100 when it used the RS-components K-type. That one, RS stock# 409-4920 costs nearly £8 (incl. VAT) and is still only rated as +- 1.5 degC, so I'd imagine the unknown one to be much worse. Side note. To use the RS K-type (or other more professional sensors) you need a K-type adapter. I use the Brymen BKB32 for around £5 from Telonic

author: davebb
author_rank: Frequent Contributor
timestamp: June 13, 2021, 11:48:31 am
content: Good afternoonThanks for the info, i hope you do get a replay from owoni will get a PT100Thanks Dave

author: davebb
author_rank: Frequent Contributor
timestamp: June 13, 2021, 01:51:27 pm
content: Hi i have just connected 99.5ohm and am getting -000.6c and it does not change after 10min so yes i will have to try a pt100,does the K type respond faster to temp change,do you know what software we can use to extract and load the firmware ,Thanks Dave

author: theHWcave
author_rank: Regular Contributor
timestamp: June 14, 2021, 08:52:11 pm
content: I mentioned a few posts ago that there is no 10min cycle in PT100 mode...Responsiveness depends a lot on the packaging. My PT100 sensor end is encased into some metal housing (like a short 6mm diameter pipe). That protects it well but makes it slower to respond than both my K-types which have the naked junction exposed.The RS-components 409-4920 K-type I mentioned before has a response time of 0.1s (datasheet). The PT100 (also RS) has no response time listed in the datasheet.I am somewhat surprised you went for a PT100 not a "reputable" K-type. Unless of course you measure mostly high temperatures or got a probe with really short and thick leads.No idea how one would load firmware. I suppose it is possible that a certain button combination gets the processor into accepting firmware sent over the serial port but so far OWON has remained silent...

author: davebb
author_rank: Frequent Contributor
timestamp: June 14, 2021, 09:04:53 pm
content: Hi i have not yet got a PT100, yes i did read that you said your meter did not do the 10min, but as mine is v1.3.0 i would test mine.i only used a resistor, i hope that we get new firmware that also fixes this,Thanks Dave

author: kwass
author_rank: Frequent Contributor
timestamp: June 16, 2021, 11:09:02 pm
content: Dave said:QuoteBut mine is! I took advantage of all the USB power stuff available for cheap and replaced the internal 5V supply with a Qi charged LiPo cell. I used thishttps://www.amazon.com/gp/product/B07M6CRQ71/Qi receiver on Amazon along with thishttps://www.amazon.com/gp/product/B08GWTBD3T/charger/booster module. I used a large Qi padhttps://www.amazon.com/gp/product/B07PYQQ1R7/that the meter fits nicely on and has an "active" green LED in front.While not necessary I added a small voltage meter so that I could see the change state of the LiPo cell all the time through the back window I installed in place of the IEC socket. Also I installed threaded inserts to make removing the cover easier.While I keep the meter on all the time, when it's "off the Qi pad" battery life is around 10 hours at full brightness, measuring volts, using a 3000mAh LiPo cell. If you reduce the brightness to the minimum setting, it will last a full day.

author: theHWcave
author_rank: Regular Contributor
timestamp: June 17, 2021, 08:44:15 am
content: @kwass: what a great mod! Very nice.Can you tell me where you got these threaded inserts from? The number of times I open mine would make this a worth-while addition...

author: kwass
author_rank: Frequent Contributor
timestamp: June 17, 2021, 02:52:48 pm
content: I used M2 size threaded insertshttps://www.amazon.com/gp/product/B07LBQFNQD/and melted them into the mounting posts. Just takes a second but make sure that they are level. I used M2 screws from this sethttps://www.amazon.com/gp/product/B07W5J4WC9/, you'll need some flat washers to match the width of the recessed case hole.

author: BugCatcher
author_rank: Contributor
timestamp: June 17, 2021, 03:16:23 pm
content: Hi kwass,battery based is an excellent feature!My private "MiniLab" is 1.4m x 1.4m. I had already a lot of trouble with interference from switched power supplies and a DECT-phone-base below the desk.Do you really use the XDM1041 during active charging? Did you observe any interference from the Qi pad (e.g. high impedance measurements)?Active Qi pad on a lab desk ... I would expect a lot of trouble!

author: kwass
author_rank: Frequent Contributor
timestamp: June 17, 2021, 04:25:05 pm
content: Do you really use the XDM1041 during active charging? Did you observe any interference from the Qi pad (e.g. high impedance measurements)?Active Qi pad on a lab desk ... I would expect a lot of trouble!Yes, I do use it during active charging all the time and I've not seen any interference from the Qi pad at all -- even on high resistance (10M+ ohm) measurements and sub-uA measurements. The Qi receiver ships with a stick-on magnetic shied and I've installed that behind the receiver coil, that might be helping a bunch. Keep in mind that this meter has absolutely no internal shielding and it was designed with a switching power supply almost touching the main PCB and it works fine.I thought that about the same potential issue before I started this project and did a bunch of testing before any modifications, just to be sure it would work fine.No doubt the Qi pad adds a lot of noise to the local RF environment, but so do many switching power supplies on my bench that operate in the same frequency range.

author: theHWcave
author_rank: Regular Contributor
timestamp: June 20, 2021, 09:35:09 pm
content: A quick update. OWON has sent me a firmware update !You need to install a special uploader program on a Windows PC, connect the XDM1041 via serial port, then point the uploader at the firmware binary, initiate the upload on the PC and turn the XDM1041 off and on. Obviously the meter sends a special message during bootup (when the screen shows the progress bar) to the uploader. The uploader detects this and sends the new firmware in chunks to the meter and then confirms whether it was successful. Instead of version 1.2, my meter now shows 20210525 (obviously a date) as a versionIn the 1 hour playing with it so far, I have not seen anything really different. Maybe the meter redraws the screen slightly faster but I can't really vouch for that. I did test capacitance mode in auto range mode and it is as bad as before (need to use manual range for >500uF ) and the hick-up every 600s in KITS90 mode is also still there.I have asked for a description of the changes and also if I can share the firmware. Will report on responses.

author: davebb
author_rank: Frequent Contributor
timestamp: June 21, 2021, 01:09:00 pm
content: HiThis is great news,I hope that they do let you post it, i would like to try it , to see if it helps my High Temp readingGreat video ,looking forward for the next one,Thanks for letting us knowThanks Dave

author: theHWcave
author_rank: Regular Contributor
timestamp: July 06, 2021, 05:55:20 pm
content: A list of all SCPI commands for the XDM1041 as far as I have discovered and tested themRegarding firmware 25052021: its has issues on SCPI. For some reason, the XMD1041 now responds to every command that isn't by itself returning something with the string OK\nOK\nOK\n (the \n being new line control characters). It does that even if you send nonsense like "hello world".I think that change is the reason that the DMMEasyControl Windows software you can download from OWON to remote-control their multimeters can't change functions anymore. The SCPI commands still work but your software now needs to deal with that nonsense response. Therefore I would not recommend this firmware change.

author: davebb
author_rank: Frequent Contributor
timestamp: July 10, 2021, 04:19:26 pm
content: Hi i have just been playing with my meter, i have been compering it against a Fluke 189 that my old work mate gave me as he has just finished work for good as he is now 70 years old he also gave me a load of crimp tools and 2c Metcal soldering irons and a box of tips for them, He said that there was a meter in the box , but i did not expect a fluke 189 in great condition, i worked with him 13 years ago, i have not seen him for about 8 years, so it is good to keep in touch by phone,the owon readings for dc voltage and resistance are very close to the fluke but what i did find is the dc current reading was out a bit, at 10 amps it was reading about 400ma low,could this be corrected in the firmware ?I do love the new to me fluke 189, peaple are still asking £370-400 on ebay for them,Thanks Dave

author: Kleinstein
author_rank: Super Contributor
timestamp: July 10, 2021, 05:03:21 pm
content: The 10 A ranges on relatively cheap meters and also with some of the better hand-helds can suffer from heating of the shunt. So especially at a high current applied for a longer time, the reading may no be very accurate with both meters. It may be better to compare the 10 A range at a low current, like 2 or 3 A. So less heating and likely a more accurate reading.The calibration procedure can likely adjust the skale factor for the 10 A range. With a modern meter this is done in software an not with an old style trimmer. Usually the factory calibration should be better than 4%, even with an OWON brand. The calibration procedure may not be openly available and may effect other ranges too - so nothing one would like to call if not absolutely needed.The 10 A range on the fluke may no be perfectly protected by the fuse, so it may have suffered over years of use. So while it is a Fluke, I would not call a reliably reference for a recalibration. It is no clear which meter is out more.

author: davebb
author_rank: Frequent Contributor
timestamp: July 10, 2021, 05:31:47 pm
content: Hiit is the owon that is reading low, not the Fluke, The Fluke is perfect, i did compare the meters at a low current,500ma and up, i have Klunkin load ,The owon reads low on the current range from mili-amps to 10amps and with 10 amps the owon is reading 9.6amps 400mAmps and 200ma low on 5amps load, i can leave 10amp on it and it does not change so i dont think it is heatThanks Dave

author: theHWcave
author_rank: Regular Contributor
timestamp: July 11, 2021, 09:56:54 am
content: How strange. My Owon was within 0.02% of the BM869S for DC current from 1A all the way to 7.5A (which is as high as I could test). The BM869S is rated to 0.5% for current (same as the XDM1041 and the Fluke 189 for that matter). From 500mA to 1A it was within 0.04% of the Agilent 34401A and from 1mA to 100mA witihin 0.02% of the Agilent 34401AEven if we assume that the Fluke is reading 0.5% too high, i.e. it shows 10A when the true current is only 9.95A and the Owon 0.5% too low so that it would read the same current as 9.9, your result of 9.6 on the Owon is way out of spec.Also the XDM1041 spec says that for >7A you should measure for a max of 30 seconds with 30 seconds off afterwards. Especially if you are ramping up the test current slowly, say to test the meter in 0.5A steps, that heat & time limit is easily exceeded as heat is of course accumulative. The Fluke has a similar time restriction but only for >10A I believe.Kleinstein has a valid point here and hopefully nothing got permanently damaged during your earlier tests. To exclude heating effects you should run accuracy tests for higher currents from cold, both meters in series and off for some time, and compare the readings in the 1st 30 seconds.

author: davebb
author_rank: Frequent Contributor
timestamp: July 11, 2021, 12:02:54 pm
content: Good afternoonThe flukes 189 spec say 10A continuous and 20a for 30secThe fluke is measuring well against my load and psu amp meter and all other meters ,anyway the shunt wire has a lot of solder on it on the shunt/ component side so i wicked some off and moved it a bit and now i am getting a reading of 32.5ma high at 5A, and 65ma high at 10A, I could Play with it some more but i am happy to leave it there,Thanks Dave

author: theHWcave
author_rank: Regular Contributor
timestamp: July 11, 2021, 03:50:24 pm
content: Very interesting. I never thought a bit of solder could have that much of an effect, I mean assuming it did not "climb" up the shunt itself. So before the shunt resistance was lower than it should have been and the meter was under-reading. Now it seems pretty much spot on (within tolerances). Glad that its working now.At the moment I am struggling with a similar problem for one of those cheap panel meters that measures DC volts & amps. The amp reading is way too high even when adjusting the trim-pot all the way down. I experimentally added a parallel shunt of 0.2Ohm and that got it nearly there. After your experience maybe I should add more solder to the shunt? I am very tempted to try that.

author: davebb
author_rank: Frequent Contributor
timestamp: July 11, 2021, 05:09:27 pm
content: HiYes, after how much difference the solder getting wicked up the legs of the shunt so yes the solder did climb up the shunt legs,i should have taken a photo, there was a lot of solder on the legs ,i may well try and get it a little bit closer, but it is working well,try tinning your shunt,you wont need much solder on there, you can always use solder wick to clean it back offIn a way i wish i had sent the meter back before playing with it, because of the temperature problem ,it does seem strange how this got past there cal and QA, as the current was way out of spec,i got a owon ow18e h/held meter to use at work as it has bluetooth and that is ok for £45, i work on a car x-ray unit it was drive thru, now we have it on a conveyor system controlled by a plc with 4x 3ph motors each with 500nm of torque,we run the xray gen at, 250kv at 3ma ,so with bluetooth i dont have to get to close when testing,Thanks Dave

author: coromonadalix
author_rank: Super Contributor
timestamp: July 12, 2021, 07:55:34 am
content: Be careful, i've seen in the past some obscure ways to calibrate a shunt with added solder on it. Not a the pcb / shunt junction but on the "wire itself" ??

author: Kleinstein
author_rank: Super Contributor
timestamp: July 12, 2021, 09:17:44 am
content: Adjusting shunts by adding solder and removing matrial with a file was common in the old days of analog meters and early DMMs. Adding solder, especially in the center of the shunt can alter the TC as the solder resistance contributes and there is also some alloying (e.g. tin is incorporated into the base material).Modern meters usually use numerical cal factors and thus calibration by a software constant.I would be a bit careful in assuming that a used Fluke handheld DMM must be accurate. Usually the factory calibration is no that bad. There can be rare exceptions, like there can be damaged DMMs.

author: davebb
author_rank: Frequent Contributor
timestamp: July 12, 2021, 09:40:10 pm
content: Hi My fluke reads fine the same as all of my good meters, It is the OWON XDM1041 that was a long way out but better nowi think they have missed some of the cal at the factory as my temp is way out as well,i should have sent it back to china to banggood but if i do any temp logging i can now use the fluke,Thanks Dave

author: markderlo
author_rank: Newbie
timestamp: October 08, 2021, 05:02:47 pm
content: post you email address or email me at ksmail9 AT protonmail.com and I will email you manual in PDF form

author: markderlo
author_rank: Newbie
timestamp: October 08, 2021, 05:05:10 pm
content: or try this link to that manual:https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjb-9HZpbvzAhVpkosKHWiqBw0QFnoECAkQAQ&url=http%3A%2F%2Ffiles.owon.com.cn%2Fprobook%2FOWON_XDM1041_Digital%2520Multimeter_USER_MANUAL.pdf&usg=AOvVaw1OUY_rrkgLrCzgycYeAVAM

author: markderlo
author_rank: Newbie
timestamp: October 08, 2021, 06:25:12 pm
content: or try this link to that manual:https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjb-9HZpbvzAhVpkosKHWiqBw0QFnoECAkQAQ&url=http%3A%2F%2Ffiles.owon.com.cn%2Fprobook%2FOWON_XDM1041_Digital%2520Multimeter_USER_MANUAL.pdf&usg=AOvVaw1OUY_rrkgLrCzgycYeAVAM

author: J_A_F
author_rank: Newbie
timestamp: October 16, 2021, 11:45:48 pm
content: Hey Everyone,I just bought one of the new revisions of the XDM1041 with USB, and I gotta say, not the most intuitive thing to set up as far as the control software goes.Figured I would share what I did in case anyone has had the same trouble as me, or to save some poor soul in the future...1. If you get one, ignore the install instructions, they don't configure the driver correctly, and nothing works. do the following:1.1 Install NI VISA (got it working on newest release, 21.0)1.2 Install CH340 drivers (the serial device used in the XDM1041). Sparkfun has an article pointing to them:https://learn.sparkfun.com/tutorials/how-to-install-ch340-drivers/all1.3 Install the DMMEaasyControl software2. Next, when you open up the control software, click control->connect in the top left hand corner3. Once it is open, choose "Via COM" instead of USB. Nothing ever pops up for USB4. It should pop up a choice like "ASRL3(DMM) (mine is configured to be COM port 3)5. Press ok and you should be good to goLike other people have mentioned, software isn't the best, but it works, does data logging, ect. so hopefully this helps someone!Also, if anyone had better luck let me know, I feel like this is a bit ridiculous

author: robdejonge
author_rank: Regular Contributor
timestamp: October 20, 2021, 04:00:08 am
content: The form factor of this dmm is what makes it appealing to me. Like some others, I have a small shelf right over my work surface and it's great to be able to just glance up at my dmm and scope. A 'proper' bench dmm would move to a shelf quite a bit higher, which is the main reason I hesitate to get something like that until I can build a deeper bench.The YouTube review videos theHWcave did were very insightful (thank you!). The voltage range issue is indeed odd, the bigger brother XDM2041does not seem to have that issue. Other than that, and based on this thread, this seems to be a pretty decent electronics bench meter!I do have a few questions ...Burden voltage: has anybody had a look at this? I mostly play with 0-5V and 0-1A stuff, so it can be a major pain.My current meterdrops the voltage by 142mV at 100mA, which is not too bad.Software: although a Mac fanboy, I run Debian on my bench computer and so wonder if there is any software available on there which I can use to control / read this mm. Does anybody have any experience? Using software to do data logging is a major reason I'm looking at this.Bar graph: I like me a nice bar graph, but I believe this meter does not have one - correct? I've recently been looking at power supplies which are showing a line graph over time, but I guess I would have seen that mode if it was present. I know, could use my scope.Might sell my current meter and order this on 11/11 if there is a good deal.Thanks for your comments.

author: kwass
author_rank: Frequent Contributor
timestamp: October 21, 2021, 03:00:44 am
content: I measured the current shunts: 500uA/5mA = 101 ohms, 50mA/500mA = 1.2 ohms, 5A/10A = 0.02 ohms. So on the 500mA range, 100mA would be 120mV drop.It's pretty standard SCPI, so I'm sure you could find some software for Debian.Unfortunately there's no bar graph.

author: robdejonge
author_rank: Regular Contributor
timestamp: October 21, 2021, 03:25:58 am
content: Thanks for checking that. This is an interesting meter indeed, with a relatively low burden voltage like that!

author: Kleinstein
author_rank: Super Contributor
timestamp: October 21, 2021, 07:05:12 am
content: The burden voltage for the 5 and 500 mA range is not low - it is more on the high side. The burden is low for the lower of the 2 ranges. The 20 mOhms for the 5/10A range is low - it this range with a fuse. Quite often a proper fuse has a comparable or even higher resistance. So part of the burden in the 500 mA range is the fuse and with this in mind the value is not that bad.For a low cost meter it still makes sense to have few shunts and share one of 2 ranges each.

author: robdejonge
author_rank: Regular Contributor
timestamp: October 21, 2021, 08:25:31 am
content: Hm, okay.So the way I look at this is that the maximum burden voltage would be 660mV. My existing meter is a Holdpeak HP-770D and has a burden voltage of142mV @ 100mAand as a 42,000 count meter would peak at 596mV burden voltage. I'm happy to be corrected, because I've been wondering if this is the right way of calculating that.Inthis overview, only the EEVblog meter has a max burden voltage that is impressively low. Not pushing back on your statement, just explaining why this novice thought 500-600mV was low.

author: robdejonge
author_rank: Regular Contributor
timestamp: October 21, 2021, 08:32:55 am
content: The Holdpeak HP-770D that I currently use is sort of ok for me. Reviews seemed to indicate it was within spec, and performing quite ok. And I've been happy with it until now.The reason I'm looking at the XDM1041 is not so much for added accuracy (it does have smaller tolerances than the Holdpeak, and a slightly higher count), but more so because 1) it is a bench meter, I wouldn't be carrying it around; and 2) it supports data logging, which would let me monitor things over longer periods of time.I'd try to sell my Holdpeak, although the market here has lots of cheap multimeters so I'm not sure I'd be able to.Generally speaking, I can't seem to make up my mind between "it's worth spending $100 on this new meter" and "you don't need this new meter"So if anyone has arguments either way, please do share!

author: HKJ
author_rank: Super Contributor
timestamp: October 21, 2021, 09:11:17 am
content: Quote from: robdejonge on October 21, 2021, 08:25:31 amTypically handheld DMM's uses 100ohm, 1ohm & 0.01ohm as current shunts with two ranges for each shunt and the high uA & mA range will have a voltage drop across the resistor similar to the high mV range. For the 1ohm & 0.01ohm there is also the fuse to account for, it will about double the resistance for the 1ohm shunt, i.e. the burden voltage will typically be about twice the high mV range (This means about 1.2V for a 6000 count meter at 600mA).A few meters are different either using lower shunt values or moving the high mA range to the 0.01ohm shunt (GW121)Quote from: robdejonge on October 21, 2021, 08:32:55 amIf you want to log on a computer, try checking TestController, it support a lot of different meters (Not XDM1041 yet). There is a long thread about it here:https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/

author: Kleinstein
author_rank: Super Contributor
timestamp: October 21, 2021, 09:28:08 am
content: The burden drop is often the same as the lowest mV range, as the mV range is used to measure the votlage at the shunt. With the older 2000/20000 count meters that was 200 mV. The meters with a 500/600 mV range as there lowest have slight problem here. The burden would be quite hight an in addition the heat produces with 600 mA and 600 mV is already quite a lot.In analog times the internal meter movement often got away with even less and a burden voltage of some 100 mV was more typical.

author: HKJ
author_rank: Super Contributor
timestamp: October 21, 2021, 10:30:57 am
content: Quote from: Kleinstein on October 21, 2021, 09:28:08 amNo, it is the highest mV range (200-600mV) for high uA and mA, if the meter has a low mV range (20-60mV) it is used for the low uA and mA range. If the low mv range is missing the internal x10 amplifier if not used for mV, only for current.

author: theHWcave
author_rank: Regular Contributor
timestamp: October 31, 2021, 11:20:53 pm
content: Have a look at my 4 part detailed review of the OWON XDM1041. I also wrote some python software for logging (works on Linux and Windows) you can download from my Github pagehttps://github.com/TheHWcave/OWON-XDM1041. This link also contains my documentation of the SCPI remote control commands implemented in the XDM1041 (quite comprehensive for what you pay).The XDM1041 has its flaws. The main one is that by default its slow (but very accurate). It allows you to select faster speeds (sacrificing some accuracy) but you have to do that every time it is powered on (it doesn't remember that setting). Oh and the auto-ranging on capacitor measurement is not working well. If the XDM1041 is your only way to measure capacitance, buy another meter. And did I mention that supporting PT100 temperature probes is well intended but useless because of the way REL mode is implemented for temperature. (K-type works better but has its own interesting quirks, watch the video or read my earlier posts on the XDM1041)...Besides the XDM1041, I have an Agilent 34401A, Solartron 7150+ , HP3478A, BM869S, BM235 and a couple of other handhelds but the XDM1041 has become my most often used meter for repair work on the bench because its so convenient, small, and always on.

author: robdejonge
author_rank: Regular Contributor
timestamp: November 01, 2021, 04:31:47 am
content: Quote from: theHWcave on October 31, 2021, 11:20:53 pmThat says a lot!

author: robdejonge
author_rank: Regular Contributor
timestamp: November 01, 2021, 04:54:37 am
content: Why does the meter require a function switch between mV and V for the VDC and VAC measurements?I recently saw a comparison of the XDM1041 and XDM2041 by Tony Albushttps://youtu.be/ZVDJSa3pxrYThe big brother of the two does not have the weird "function switch" requirement. But it seems to be using the same software or at least software framework. I'm curious what would necessitate the requirement of such a switch in the software. Is there a hardware reason? Or could we (let's not hold our breath!) eventually see Owon correct this issue in a firmware update?

author: theHWcave
author_rank: Regular Contributor
timestamp: November 01, 2021, 08:09:55 am
content: You are right, there isn't a hardware issue for that as far as I can see. At least for volts... It needs to do the same for current but there the reason is that A and mA/uA use different input sockets. Could be something with the HY3131 front end? But nothing that the firmware could not fix. Does Dave's 121GW do the same thing? It has the same front end chip. OWON is sluggish at best responding to bug reports. What I hope is someone writing completely new software. This meter looks to be very hackable, since the front end used just an SPI interface and I think 2 discrete signals to drive relays

author: Kleinstein
author_rank: Super Contributor
timestamp: November 01, 2021, 10:07:49 am
content: The separate mV and V ranges are a bit odd. It could be just avoiding the very long list of voltage ranges, that may not fit the screen. This should be a SW only issue.It is interesting that the reading rate via the PC interface is quite a bit higher than with the updates on screen.For the K-type thermocouple it does not really mater if the temperature is ITS90 or a different curve - the differents are so much in the details not even the 34401 with a PT100 may notice.

author: ciccio
author_rank: Frequent Contributor
timestamp: December 17, 2021, 03:01:35 pm
content: I received my meter form Banggood yesterday.First impression was positive, but when I checked temperature measurement, I discovered that readings from a know good PT100 vere off, sometimes very off. Reading increased slowly from 21 to 160 °CMy resistance box was not available, so I checked at three resistance values, and it was almost correct at 0, 100, 200 ° C.Will check later with a better decade box.As for thermocouple, the data sheet says K type, but the meter allows to select "LOAD" (why Load and not Source? ) as PT100 and KIT90 TC, which I discovered being a new designation for K type.With a known good TC, it seemed to read correct values.I will examine cold junction compensation as soon as I'l have a free evening.The software installation was a nightmare, I will try next week on a Windows 10 PC.My Windows 7 work machine seems to be allergic to N.I. VISA32 installation.I had the same problem with the software for a JUNTEK function generator.Best regards

author: BugCatcher
author_rank: Contributor
timestamp: December 29, 2021, 04:57:36 pm
content: theHWcaveReceived my XDM1041 a few days ago (running V3.0.1 SW). During waiting for delivery was enough time to screen all available information.Found interesting discussions regarding different types of temperature sensors.Regarding PT100 sensors I found following arguments:- calculations for temperatures < 0°C are more challenging- unwanted cable resistance is adding huge errors at low temperatures (around °0C)Regarding temperatures < °0C:Calculation requires 3rd-order polynom (pos. temperatures only 2nd-order)What happens when we simply ignore the 3rd-order coefficient "c"?at -100°C an additional error of 0.2°Cat -50°C an additional error of 0.02°C-> see first diagram ... (including tolerance band for class A sensors)=> extreme unlikely that "home lab" applications will ever face temperatures below -50°C=> second order correction is sufficient! No need to block calculation for <0°C!Regarding impact of cable resistance:I calculated the impact of an given resistor (0.262Ohm). Precise calculation based on the 3rd order polynom.- impact nearly flat, no singularity around 0°C- simply subtract 0.7°C for a "good enough" correction (rule of thumb: subtract 2.6°C per Ohm, perfect at 50°C)-> see second diagram-> there is no problem for bench applications without extreme cable lengthDuring ordering PT100 sensors I found that there are also PT1000 devices!Price for class A PT100/1000 unpacked sensors is below 2€ (e.g. Reichelt in Germany)-> PT1000 reduces the impact of the unwanted resistance by one magnitude (green line)!Problem:XDM1041 is not supporting PT1000! ... Why? It's a huge benefit with nearly no effort (measured resistance divided by 10)!The only solution is an external PC-SW with a very simple modification of the PT100 algorithm.e.g. XDM1041 utility from theHWcave ... btw: this is an impressive piece of work!!!Another idea: SW-feature to enter the cable resistance manually (no need for a 3-wire cable!)... only need for a one time resistance measurement at known temperature (e.g. 0°C ice-water)!I tried to install the utility on a Windows10 system running Python 3.10 ... I failed!What must be preinstalled? Did it ever work on Windows10?Regarding comparison of Thermocouple/PTxx ... I found an interesting link:https://tmseurope.co.uk/applications/thermocouple-rtd-colour-codes-tolerances-> Below 400°C PTxx class A shows always the best precision!My own preference is PT100/1000:- low price- good performance- heading for PT1000 with external SW- full precision after cold start ... no trouble with reference junction block- only negative point: TCs can handle higher temperatures

author: theHWcave
author_rank: Regular Contributor
timestamp: January 02, 2022, 06:44:58 pm
content: For anyone interested, I have put the OWON Windows tool to upgrade the firmware of the XDM1041 as well as the firmware version OWON sent me (apparently V2.1.2 however it shows as 20210525) on my github page. The tool should be able to upload other firmware versions as well.You can download it (in binary chunks) here:https://github.com/TheHWcave/OWON-XDM1041with instructions in the readme file to reassemble the .ZIP file(the reason for breaking it into chunks is the file size limit on Github)To be clear, this is OWON's software but they gave me permission to post it. Don't complain to me about the quality of either the upgrade tool or the firmware pleaseFrom the same place, you can download my own software (happy to accept suggestions on that) to log data from the XDM1041 on a PC (Linux or Windows), including a mode to properly use a PT100 sensor to measure temperature.

author: BugCatcher
author_rank: Contributor
timestamp: January 04, 2022, 01:41:33 pm
content: XDM1041 Continuity TestI had the impression that the response time is related to the XDM1041 "beep-threshold".All existing evaluations regarding "speed of continuity beep response" are based on "hectic moves" combined with gut feeling!I would like to propose an objective test method- a function generator (square wave, 1Hz, variable duty cycle)- a "contact" controlled by the function generatorthere are two options- a FET, I used a 2N7000 (2.1Ohm on resistance)- a reed relais (typ. 0.15Ohm on resistance, switching time about 1ms)- I also increased the "on" contact resistance by adding different serial resistors (10, 30, 100Ohm)Measurement procedureIncrease the "on" time by changing the duty cycle of the square wave- first you hear single beeps (not every second)- increase "on" time until you hear every second a beep-> this is the minimum time for the reliable detection of "contact"The diagram shows my results for the XDM1041- response time is heavily impacted by the "threshold resistance"- high threshold gives you very fast response- the setting of the threshold value depends on your application!I tested also an UNI-T 804- fixed threshold (40Ohm)- 2.1Ohm 180ms10Ohm 170ms30Ohm 170msWhat about other multimeters? Now we can compare!Conclusion: no longer need for "hectic moves"

author: HKJ
author_rank: Super Contributor
timestamp: January 04, 2022, 02:24:09 pm
content: Quote from: BugCatcher on January 04, 2022, 01:41:33 pmNot really, I have reviewed a lot of multimeters where I used something similar:More about it:https://lygte-info.dk/info/DMMTesterACSwitch%20UK.htmlMy Reviews:https://lygte-info.dk/info/DMMReviews.html

author: BugCatcher
author_rank: Contributor
timestamp: January 06, 2022, 09:44:10 pm
content: Good News: XDM1041 Recording FunctionXDM1041 running V3.0.1DMMEasyControl, Version 1.7.0 running on Win10Local recording and upload of data- local XDM1041 recording is working- DMMEasyControl supports upload from XDM1041 to host (slow speed, takes time)- import of uploaded data into spreadsheet (OpenOffice)special characters for °C, °F and Ohm are a challengemy solution: open data-file with text editor, copy "strange characters",past the "strange characters" as "separation characters" into the import menu of the spreadsheet,not elegant ... but working!Data retention- power off, 1h later, power on: recorded data still there- disconnected power cable, disconnected usb-cable, reconnected power (30min later): RECORDED DATA IS STILL THERE!didn't invest more effort to evaluate max. storage timeBig question:Will OWON also support PT1000Hope they are reading this thread ;-)

author: UniSoft
author_rank: Frequent Contributor
timestamp: January 08, 2022, 04:00:42 am
content: Quote from: BugCatcher on January 06, 2022, 09:44:10 pmThe big question is where to get that firmware?Quote from: BugCatcher on January 06, 2022, 09:44:10 pmIt is saved inside MCU's flash...Number of guaranteed program/erase cycles before failure (Endurance): 100 kcycles (according to the datasheet)And by the way, data and settings can be lost due power failure within erase/write sector.

author: BugCatcher
author_rank: Contributor
timestamp: January 08, 2022, 08:27:14 am
content: There must be a battery on board. Clock is running without external power supply! The question is the size of the internal SRAM ...

author: theHWcave
author_rank: Regular Contributor
timestamp: January 08, 2022, 06:50:36 pm
content: Maybe a dumb question but are you sure that the data "saved" by DMMeasycontrol" is actually your locally recorded data? I am asking because DMMeasycontrol had that save-the-recording-as-spreadsheed function before and what it actually did was record new data coming in from the meter online into the spreadsheet. It did not even look at the previously recorded local data.

author: UniSoft
author_rank: Frequent Contributor
timestamp: January 08, 2022, 08:14:10 pm
content: Quote from: BugCatcher on January 08, 2022, 08:27:14 amYes, there is a battery, for clock...I draw the schematic of the control part, attached...Quote from: BugCatcher on January 08, 2022, 08:27:14 amIf you mean SRAM of MCU, then it is totally 48KBIf you mean storage, then how I said it is stored in FLASH, maximum 1000 pointsI am working on reversing firmware...Funny part, that the firmware is written for STM32F103 MCU (using SPL libraries), but they run it as is on GD32F303

author: BugCatcher
author_rank: Contributor
timestamp: January 08, 2022, 09:15:07 pm
content: Proof of Recording FunctionI tried to make the check waterproof!- step 1 I disconnected USB from XDM- step 2 XDM power on- step 3 Temp -> PT100 -> °C- step 4 Record -> Manual -> Clear buffer -> Back- step 5 Auto -> set 20 Points -> Interval 1s- step 6 soft key Starttouched PT100 during measurement (increase/decrease of temperature)- step 7 checked samples on XDM (increase/decrease of temperature) -> was ok- step 8 XDM power off, removed PT100 cable- step 9 reconnected USB- step 10 XDM power on (running VDC, no PT100 connected!)- step 11 started DMMEasyControl on PC- step 12 DMME command Control -> Connect- step 13 DMME command Record -> Device data export -> entered path/file-name- step 14 after a few seconds: "Device data export completed!"- step 15 checked file on PC ... identical with manual observation on XDM -> BINGO!Stored file:NO MODE VALUE1 Period 29.1¡æ2 Period 29.0¡æ3 Period 29.3¡æ4 Period 29.4¡æ5 Period 29.5¡æ6 Period 29.6¡æ7 Period 29.7¡æ8 Period 29.8¡æ9 Period 29.8¡æ10 Period 29.9¡æ11 Period 29.6¡æ12 Period 29.0¡æ13 Period 28.6¡æ14 Period 28.3¡æ15 Period 27.8¡æ16 Period 27.4¡æ17 Period 27.0¡æ18 Period 26.8¡æ19 Period 26.5¡æ20 Period 26.5¡æOther observation:direct capture with DMME- you get higher resolution- you get date/time on toponly problem: formatting of msec is not correctcorrect example for time: 19:22:47.779incorrect example: 19:22:50. 45-> leading zeros for msec below 100 or below 10 are replaced by "space"-> trouble with spreadsheet processing

author: BugCatcher
author_rank: Contributor
timestamp: January 09, 2022, 09:11:03 am
content: UniSoftYou are right! Data must be in Flash. Leakage of SRAM (deep sleep) is above 100uA.BTW: Could it be that D1 (in front of battery) is in wrong direction?

author: UniSoft
author_rank: Frequent Contributor
timestamp: January 09, 2022, 11:34:07 am
content: Quote from: BugCatcher on January 09, 2022, 09:11:03 amI saw it in the firmware code.Quote from: BugCatcher on January 09, 2022, 09:11:03 amYes, for sure... I made a mistake.By the way, Does anyone know what the TFT display is used there.I did not find anything with such a pinout.PB2 - D/C (0: Command; 1: Data)PB10 - CLKPB1 - Probably RESET

author: BugCatcher
author_rank: Contributor
timestamp: January 10, 2022, 07:13:45 pm
content: Next Story: Sampling RateThe data sheet promises up to 65Hz sampling rate (15.4ms)First step:timing onlyI started with the DMMEasyControl tool- simple measurement due to time stamps in download,1000 samples per run (DCV, 5V fixed, fast mode)set sampling rate (ms) measured sampling rate (ms)16 51.118 51.120 48.025 50.630 51.240 52.250 77.9100 110.11000 1007.8-> Dramatic overhead for sampling rates below 1s!-> Time stamps are heavily impacted by jitter (a few 10ms)Next test is XDM with internal recordingDue to missing time stamps only total time for 1000 samples (hand stopped)15ms -> 15s30ms -> 30s100ms -> 100s-> Internal recording of XDM looks ok!Next step:What about the quality of the stored measurements?Used a function generator with a slow triangle wave (below 100mHz)downloaded an internal recording of the XDM(see "XDM_internal_recording)-> looks ok! No Jitter!Next test is DMME recording with 50ms samples. Big surprise ...- samples are repeated!- new sample value only after a few 100ms, heavily impacted by jitter!(see "DMME_repetition_of_samples")What happens for 1s sampling?- no longer repeated samples- impact of jitter still visible(see "DMME_jitter_at_1s_sampling)Potential explanation:- rate for new sample values is similar to rate on PC-display (in the range of 2Hz)- DMME SW is doing nasty things: delivering correct number of requested samples, updateof sample value only in sync with display of PC-screenMy conclusion:-> for sample rates below 1s you have to use the internal recording!

author: Ringmodulator
author_rank: Regular Contributor
timestamp: January 12, 2022, 12:51:08 pm
content: Check out the Voltcraft VC-655 BTLooks like the same unit in a different dress....https://asset.conrad.com/media10/add/160267/c1/-/en/002357060DS00/datenblatt-2357060-voltcraft-vc-655-bt-tisch-multimeter-digital-cat-i-1000-v-cat-ii-600-v-anzeige-counts-55000.pdfChris

author: Johnny B Good
author_rank: Frequent Contributor
timestamp: January 18, 2022, 04:31:58 pm
content: It appears to be the same breed of "Duck", you know, if it walks like a duck, quacks like a duck...At nearly 200 Euros (and possibly VAT on top - there didn't seem any point checking at that pricing level) for the Voltcraft version, I decided to spend my money on the Banggood offering, namely the OWON XDM1041 USB model for just £96.46 plus a little extra on shipping and tariff insurance (still just under the 99 quid mark with an estimated delivery by the 29th - a realistic estimate going by recent past experience).

author: Ringmodulator
author_rank: Regular Contributor
timestamp: January 21, 2022, 08:28:52 pm
content: Quote from: Johnny B Good on January 18, 2022, 04:31:58 pmIt is currently 139,99€ with VAT and shipping included. Add VAT and conversion to € for your Banggood offering, you are about level.https://www.conrad.de/de/p/voltcraft-vc-655-bt-tisch-multimeter-digital-cat-i-1000-v-cat-ii-600-v-anzeige-counts-55000-2357060.html

author: Johnny B Good
author_rank: Frequent Contributor
timestamp: January 22, 2022, 03:14:40 am
content: I just checked the currency exchange rates and I reckon I saved close to £20.00 on the deal (Banggood only show VAT inclusive prices, at least to us Brits). What I'd paid, was the equivalent of 119€ in total with no further charges added on.

author: Johnny B Good
author_rank: Frequent Contributor
timestamp: January 26, 2022, 05:41:49 pm
content: The XDM1041 I'd ordered from Banggood arrived this morning - three days sooner than Banggood's estimated delivery date.I haven't tested everything but it seems to be within its specs on DC volts and K-type temperature readings. The standby energy consumption is a gratifyingly low 250mW, peaking to a maximum of 1.5W at a backlight level of 100% dropping to just below 1W at 0% and just a fraction over 1W at the 25% setting.I'm monitoring the EFC voltage difference against my GPSDO's internal +2.0000 voltage reference offset which is hovering around the 366.00mV mark (2.36600v) closely matching the mV readings of a Mestek DM91A 9999 counts true RMS dmm I'd been using to see these variations down to a resolution of 0.1mV.I could use it to monitor the full EFC voltage (2.3660 volts) direct but I'd end up seeing only the same effective 100uV resolution I was getting with the Mestek DMM and a +2 volt offset.The only thing that had initially put me off buying this 4.5 digit bench meter was the lack of any tempco specification, hence my pushing the boat out on an SDM3065X which has impressively low tempco figures.In this regard, I don't expect the Owon bench meter will do any better than the Mesteks which, until I had cause to test their temperature stability a few months ago, had seemed remarkably stable in the face of typical changes in room temperature.At least the Owon bench meter isn't going to incur regular changes of a pair of AAA cells every 400 hours of run time (I usually disable the auto shut off time out feature built into the Mesteks to avoid losing sight of whatever I'm monitoring for hours long periods).I'll give the Owon a more thorough work out later and report the results here in a follow up post.

author: Johnny B Good
author_rank: Frequent Contributor
timestamp: January 28, 2022, 03:27:24 pm
content: I completed my tests and, with the obvious exception of capacitance measurements being extremely slow to obtain results, everything else checks out with remarkably good accuracy against the SDM3065X.The only real complaint I have is in regard to the slowness (glacial) in producing capacitance readings. The accuracy of capacitance measurements is on a par with those obtained with other test meters so no complaint there - it's just the very long time required to get the reading that's so intolerable.Luckily, I have much better alternative ways to test capacitors, so this is very much far from being a "deal breaker" (as I suspect will (should!) be the case for most other purchasers).

author: BugCatcher
author_rank: Contributor
timestamp: January 28, 2022, 04:01:07 pm
content: Hi John,happy to hear that you like your new "investment"!I'm eager to get the following information:Which FW-version is running in your box?BugCatcher

author: Johnny B Good
author_rank: Frequent Contributor
timestamp: January 28, 2022, 09:11:53 pm
content: @BugCatcherV3.1.0

author: ass20
author_rank: Regular Contributor
timestamp: January 29, 2022, 08:56:24 pm
content: forUniSoftI check photo(digital board) of xdm2041 and xd1041 and found more identifical partsseehttps://github.com/PetteriAimonen/owon-xdm2041-infohttps://github.com/aziemer/Project-Phoenixandhttp://essentialscrap.com/owon_fix/

author: raphaelCoelho
author_rank: Contributor
timestamp: February 05, 2022, 12:47:21 am
content: Has anyone tried replacing the SMPS with a linear power supply, as commented on in post #51?

author: kwass
author_rank: Frequent Contributor
timestamp: February 05, 2022, 04:33:17 am
content: Quote from: raphaelCoelho on February 05, 2022, 12:47:21 amYes, see post #113 in this thread. My xdm1041 has been running continuously on a lipo cell with wireless charging for the past 8 months or so. I never turn it off and just pick it up off the changing base when I need to use it off the workbench. No problems at all, other than the bugs reported above for version 2.xxxxx firmware.

author: raphaelCoelho
author_rank: Contributor
timestamp: February 05, 2022, 06:56:02 pm
content: I had already seen your modification, it was very good!My idea is to put a small transformer and make a regulated power source. In this way try to escape some noise from the original switched power source.

author: Kleinstein
author_rank: Super Contributor
timestamp: February 05, 2022, 07:54:47 pm
content: As far As I see it, there is still a ready made DCDC converter to power the analog part. So the SMPS noise may not be the relevant noise source.The DMM chip set uses a SD-ADC that could have simultaneous 50/60 Hz supression. It still needs the correct clock frequency. I remember seeing a change in the clock for the XDM2041 that is internally similar. Has someone checked if the clock is correct for mains hum suppression ?Edit:From the pictures it looks like they have the same 4 MHz clock and may thus have a similar poor mains hum suppression problem as here:https://hackaday.com/2021/07/14/fixing-noisy-measurements-on-an-owon-xdm2041-bench-multimeter/Changing the clock could still be tricky as this may also effect seriel speed.

author: raphaelCoelho
author_rank: Contributor
timestamp: February 06, 2022, 01:41:04 am
content: I already read about it...What it seems is that the problem happens when the main power frequency is 50Hz, on the 60Hz it doesn't.Anyway, a linear power supply, with transformer, isolated from the network, could not improve the performance of the DMM?

author: Kleinstein
author_rank: Super Contributor
timestamp: February 06, 2022, 09:24:08 am
content: An old style 50/60 Hz transformer would have some advantage, as it does not have as much higher frequency common mode bakcground and could get away without a Y cap. It is still not sure if the improvement would be very visible. It could be worth a try - at least for a quick test with an external power supply. User kwass may be able to tell how much improvement he sees.The 4 MHz clock is slightly better for 60 Hz than for 50 Hz, but still not really good. So I don't understand why they don't use the correct crystal - that frequency is available (some 50 cents at Mouser) and the 4 MHz one should be only marginal cheaper, if at all.It looks like the interface to the DMM chip is SPI and thus not sensitive to the clock. So changing the clock should be OK, though it will invalidate the calibration, not just for the frequency measurement. Chances are the BW for AC RMS would also go up a little.

author: Johnny B Good
author_rank: Frequent Contributor
timestamp: February 06, 2022, 02:23:38 pm
content: From all the teardown videos I've seen and what's been said here, I reckon replacement of the 5v 2.1A smpsu board with a conventional analogue, mains transformer based psu will be a total and utter waste of time and energy (both yours and that of its annual electricity costs).As it stands, it only draws a maximum of 1.5W (NOT the claimed 15W which seems to be a typo that lost the decimal point). At a 25% backlight setting, it only draws a tad less than 1W and just a tad over at the 50% setting. Since, unlike a signal generator, all of that input energy lands up heating the bench meter's innards. Indeed, when measuring current, the thermal load sees an increase over and above that basic energy input (another watt when testing a 10A current with (afair) a 0.01 ohm shunt).In view of all those downsides, such a psu mod seems doomed to failure in its primary goal of improving the bench meter's noise immunity and performance stability. IOW, I'm strongly suggesting that you don't waste your time (let alone the costs) of replacing the existing smpsu board.

author: BugCatcher
author_rank: Contributor
timestamp: February 06, 2022, 02:40:47 pm
content: I did a few simple experiments:- recorded the voltage of two alkaline cells (5V fixed, slow mode)The Owon DMMEasycontrol App is recording the gain-corrected 24bit ADC-data. Thisis equal to a 6.5 digit resolution. That's resolution, not precision! -> see diagram-> No visible noise problem!(the spacing of the horizontal lines is 0.1mV ... equals the resolution of the displayed measurement results)- resistance modetwo 1m long banana-cables are hanging down "flapping in the breeze", not twisted. Cables are a few cm away from a 230V/50Hz cable-> reading: 50MOhm-range "overload"connected a 20MOhm resistor at the end of the banana-cables-> when I'm sitting still -> stable reading with the normal 1 unit quantization noise-> when I'm moving -> up to 20..30kOhm variation-> a few kOhm even if I'm a few meters away-> Pure electrostatic effect! No 50/60Hz interference!I don't see any problem!

author: Kleinstein
author_rank: Super Contributor
timestamp: February 06, 2022, 05:10:52 pm
content: The performance looks really good for a 50000 count meter. There is quite a bit extra resolution for the PC, though not clear about the stability and accuracy. The battery may actually show some drift.The 1 sample per second mode may have good hum suppression even if the integration time is no matching full multiples of 20 ms. To get a good response on the screen, more than 1 SPS (midium speed mode) may be the more relevant case. This would be more sensitive to hum and thus the better mode for a test to hum sensitivity.The example with the batteries is likely low hum anyway.The high resistance case would be an example that can be sensitive to hum, but here things can even get nonlinear, especially relatively close to the end of the range.To judge how good or bad the 50/60 suppresion is would better use a defined identional 50 Hz part. So maybe look at 1 V RMS 50 Hz int the 5 V DC range and record the data to see if there is some beat frequency / residual AC visible.A SD ADC can have a different filter from the SINC response one gets for simple integration over a fixed time (e.g. dual slope ADC). It still helps to have the frequency about right. Looking at the hum suppression at different frequencies could give an idea about the fitler used and how much a different clock could change. Loosing the calibration is still a good reason not to change the HW.

author: BugCatcher
author_rank: Contributor
timestamp: February 06, 2022, 06:05:43 pm
content: Voltage drift is most likely dominated by temperature of battery.Beside TC and PTxx a third method for temperature measurement ;-)Additional information regarding high impedance measurement:before adding the 20MOhm resistor- switched mode to ACV- could measure 450mV AC-voltage-> that's an indication for 50Hz attenuation ... at least sufficient for normal use cases!The Owon app has pros and conspro- extended resolution- unlimited recording lengthcon- sampling rate heavily impacted by jitter (see the two diagrams)the XDM internal recordingpro- more precise sampling rate- faster samplingcon- limited number of samples- only "original resolution"

author: Johnny B Good
author_rank: Frequent Contributor
timestamp: March 02, 2022, 05:29:12 am
content: Quote from: theHWcave on June 13, 2021, 09:32:23 amI've been trying,without any success, to obtain K-type to 4mm 19mm spaced banana plug adaptors thatdo actually usechromel and alumel pins as per a set of four cheap mini K-Type plugs I'd bought to upgrade my collection of K type TCs and was wondering if that BKB32 adaptor would be worth buying.I tried to track down information regarding the proper use of chromel/alumel pins in the BKB32 without any success. The only ones I've seen that boast the use of chromel/alumel pins are the rather ubiquitous cheap Chinese ones of which I'd purchased two on the strength of this claim (shown in the attached image below). Unfortunately, they both failed the magnet test rendering this boast a work of fiction.I suspect that, since there is no significant temperature differential with battery powered hand held meters, the BKB32 adaptor will very likely not be using chromel/alumel pins so I was wondering if you'd care to verify whether this is the case or not with a magnet test?Incidentally, I've just discovered that the HI socket runs 0.5K cooler than the LO socket which seems to be about 1.5K above ambient (the SDM3065X sockets both run within 0.1K of each other, about another 1.5K higher again).Neither of these meters can really do any justice to K type thermocouples, the Owon because of its reliance on the meter behaving like a mW powered hand held with hopefully, some sort of calibration offset applied to approximate the difference between its internal temperature and ambient, and the expensive 6 1/2 digit Siglent for its reliance on seemingly very rare chromel/alumen K to banana plug adaptors to ensure that the isothermal reference extends all the way into the socket where it measures the reference temperature at the back of the LO banana jack inside of the meter's significantly warmer interior.The Owon, once warmed up, performs almost as well as the Siglent in regard of K type thermocouple sensors. The Siglent has the potential for better accuracy if only a chromel/alumel adapter could be found to maximise the benefit of chromel/alumel mini K-type plug ended thermocouples.If you need a very fast response thermometer with better accuracy, those cheap Chinese TM-902C K type thermometers seem a cost effective way to go regardless of whether you use chrome/alumel mini-K plug ended thermocouples or not.The later versions which use a pair of AAA cells, only draw 0,35mA from the battery, a mere 1.5mW, barely enough to raise the temperature by more than a few tens of mK which significantly simplifies the issue of reference end compensation and any need to use chromel/alumel in the mini K type socket or the thermocouple plug. The biggest source of uncertainty will most likely come from the warmth of your hands but you can always get round that issue by wearing winter weather gloves or an oven mitt,

author: Kleinstein
author_rank: Super Contributor
timestamp: March 02, 2022, 08:27:05 am
content: The material in the adapter plugs does not have to be actually Alumel / Chromel like a type K thermoelement. The temperature difference over that adapter part is quite small (e.g. < 1 K) and the temperature range is small. So a different alloy with similar thermal EMF is OK. This also applied to thermo couple extension cables. With type K this may still be lower grade Alumel / Chromel, but for something like the plugs other materials that are easier to machine can be a justified alternative.If the adapter / plug part is small and thermally isolated the temperature difference over the plug is very small (e.g. < 0.1 K) and the material does not really matter. Littel heat flow also helps with the meter internal temperature gradients. So a good thermal design can be more important than the "correct" material.If higher accuracy is needed, the option would be to use an external electronic cold junction compensation. That is a small external circuit to correct for the cold juntion and give the TC voltage as if the cold junction temperature would be 0 C. The meter would than measure voltage and the conversion would be done on the PC side or as a math function. I have used such small yellow units from Omega, that were powered by a single Li cell and worked quite well together with HP3478 / 3457. For some reason they seem to be no longer available and alternative one are quite expensive.If multiple channels are needed, an external DIY cold junction box with a sensor could be an alternative. The temperature may be stable enough to only need a single reading. The scanner cards for DMMs often include a reasonable cold junction sensor, much better than via the normal inputs.For the SDM1041 the slight problem is that there is no really good low voltage range and the resolution may be limited. There may still be enough resolution via the PC interface.

author: piit79
author_rank: Newbie
timestamp: April 12, 2022, 01:21:16 pm
content: Quote from: UniSoft on January 08, 2022, 08:14:10 pmI'm very glad to hear that! Out of curiosity, any progress? The ONE thing I'd like to see fixed/patched somehow is the LONG delay on startup - it's very annoying. I wish I could just short-press the power button to put the meter on :/

author: kwass
author_rank: Frequent Contributor
timestamp: April 13, 2022, 12:20:58 pm
content: Quote from: piit79 on April 12, 2022, 01:21:16 pmI agree. My solution is to just leave it on all the time. Mine's been on for almost a year with no ill effects and power consumption is negligible.

author: UniSoft
author_rank: Frequent Contributor
timestamp: April 13, 2022, 06:53:38 pm
content: Quote from: piit79 on April 12, 2022, 01:21:16 pmNope... I put the project on pause...I can't find latest firmware (or at least same version as mine), to start testing etc..Need to extract bootloader first, and to do this I need to write custom code, what will erase current firmware, so I will not be able to restore the same version.There is only old versionposted by @theHWcave.It actually stops me from further experiments.Shit OWON no even reply for request of update.Quote from: piit79 on April 12, 2022, 01:21:16 pmThis can't be changed by firmware...Power switch is implemented by standalone MCU ATTINY202-SSF...It is really not hard to write firmware for this MCU. But it cannot be updated via USB/COM.

author: BugCatcher
author_rank: Contributor
timestamp: May 15, 2022, 11:15:36 am
content: Owon released a new version of the XDM1041!The newXDM1241offers internal lithium battery instead of AC power. All other features look identical ...Banggood is already offering the new device!http://files.owon.com.cn/probook/OWON_XDM1000_Digital%20Multimeter_USER_MANUAL.pdfBugCatcher

author: mapleLC
author_rank: Frequent Contributor
timestamp: May 16, 2022, 12:52:03 am
content: Trying to understand why anyone would want this.

author: Johnny B Good
author_rank: Frequent Contributor
timestamp: May 16, 2022, 12:53:28 pm
content: Consumer demand?

author: Kleinstein
author_rank: Super Contributor
timestamp: May 16, 2022, 01:09:31 pm
content: Battery operation has its advantage: no power cable needed and better isolation / less common mode signal injection to worry about. Even if the possible injection of a common mode signal is not often a problem it helps if you don't have to consider this as a possible source of an unexpected signal.With the moderate power consumption operation on a rechargible battery and still have a well visible screen is nice. Keithley / Fluke had early 4.5 digit bench top meters with battery option, so it is not a new invention.

author: mapleLC
author_rank: Frequent Contributor
timestamp: May 16, 2022, 02:23:36 pm
content: Quote from: Kleinstein on May 16, 2022, 01:09:31 pmQuote from: Johnny B Good on May 16, 2022, 12:53:28 pmI'm one of those consumers that demands a bit more reputation, so this is my old workhorse. While reputation is on the decline, period specific, reputation still matters.I wouldn't trade mine for yours.

author: akisnas
author_rank: Newbie
timestamp: May 29, 2022, 07:13:17 am
content: Hello everyone, i bought 2 of them a few months before, tested and then storage in original boxes for 2 -3 months before my project started.Today unpackage and i test them, both of them were dead no powered at all.I notice the psu is working and 5V is present, have you any idea what is going on?Is there any member with the same issue?The rechargeable battery MS621FE measured at 2.6V.Do you think there is an issue with this battery?Its really weird...Thanks for your time.Best Regards

author: akisnas
author_rank: Newbie
timestamp: May 29, 2022, 07:35:56 am
content: Problem solved, after 10mins the battery charged and its working again.

author: sigxcpu
author_rank: Regular Contributor
timestamp: June 23, 2022, 01:02:48 pm
content: I will leave this information here, for all others that may be hit by my problem.I've tried to use the utility & firmware provided herehttps://github.com/TheHWcave/OWON-XDM1041/tree/main/OWON%20firmware, but the meter didn't exit bootloader/restart - finished with error at "checking new version".I tried to re-flash lots of times with the same result.Diode/continuity was broken (showing 0 and beeping continuously), "Utility" menu was also broken. Most likely the "calibration" data was corrupted.I wrote to Owon but I didn't get any response yet, then I've found this repositoryhttps://github.com/PetteriAimonen/owon-xdm2041-info/tree/main/bootloaderand a crazy idea was born. What if I write the calibration data from 2041 (thank you PetteriAimonen) to my 1041?To my surprise, it worked, the meter is fully functional again and, based on few tests I did, accurate enough.Of course, now it thinks it is a 2041 on version 1.7.2 (the actual version is 2.1.2), but I can live with that.Attached a picture with the broken "utility" menu.LE: If somebody would be kind enough to dump the calibration data from their 1041, I would be forever thankfulThe script to do that is herehttps://github.com/PetteriAimonen/owon-xdm2041-info/blob/main/bootloader/backup_calibration.py

author: mapleLC
author_rank: Frequent Contributor
timestamp: June 27, 2022, 06:39:59 am
content: Quote from: sigxcpu on June 23, 2022, 01:02:48 pmWhy don't you call Chinese customer service bro?

author: UniSoft
author_rank: Frequent Contributor
timestamp: June 27, 2022, 03:37:23 pm
content: If someone interested, there is a hidden calibration menu (I saw it in code)UTILITY-MATH-UP-RANGE-DOWN : Enter manual calibration mode (MATH for exit)DO NOT RUN IT!!!You will lose all calibration values!!!It requires some additional equipment.UTILITY-DUAL-UP-RANGE-DOWN: Enter automatic calibration mode (I never run it)

author: msquared
author_rank: Regular Contributor
timestamp: June 27, 2022, 07:39:31 pm
content: Here' the cal data from my XDM1041. Hope this helps.

author: Markus2801A
author_rank: Regular Contributor
timestamp: June 29, 2022, 12:21:47 pm
content: Quote from: BugCatcher on May 15, 2022, 11:15:36 amHas anyone ordered the battery powered XDM 1241 version?I ordered it a few weeks ago but then got the email that something went wrong with delivery and the package was returned.Banggood immediately offered a refund, so I don't know should I try it again? is it worth?

author: theHWcave
author_rank: Regular Contributor
timestamp: July 01, 2022, 08:06:32 am
content: Quote from: UniSoft on June 27, 2022, 03:37:23 pmThat is cool! But in mine I get a DEBUG, KEY, and LCD menu for the first sequence. The KEY and LCD menu are tests for checking key response and LCD, the DEBUG shows two additional values in the normal measurement menus which are called ZERO and COEF. Are these the calibration constants? They appear to be editable. For example in the 5V DC range ZERO is 0000000 and COEF is 0800000 in mine.The 2nd sequence seems to run a program automatically (no choice, it starts right away) that shows all cal values line by line for all ranges. it is possible that this expects inputs for calibration but it runs quite fast not waiting for inputs. I might possible use the serial port to communicate with a calibrator connected... Yes, it appears that's what they do in the factory with an automated calibrator attachedDONT RUN IT! I completely lost calibration on all ranges! !!I do have a dump of my CAL values, now to see if I can load it back ... will report on it

author: theHWcave
author_rank: Regular Contributor
timestamp: July 01, 2022, 08:18:21 am
content: Ok, using the first DEBUG menu, I managed to get the 5V DC range back. I connected the meter to my DMMCheckPlus reference of 5.0000V and changed the COEF value which did change the reading on the display. Strangely when I hit the RUN/STOP key the COEF jumped to a value which corresponds to exactly 5V. The other ranges are all still hosed. So, manual cal works but I still need to see how to reload the cal dump.

author: theHWcave
author_rank: Regular Contributor
timestamp: July 01, 2022, 01:28:20 pm
content: Luckily i had made a recent dump of all CAL data and was able to reload that just now. Everything seems to work as beforeFor all you XDM1041 users: Petteri Aimonen's tools to save and load CAL data are herehttps://github.com/PetteriAimonen/owon-xdm2041-info/tree/main/bootloaderThey are for XDM2041 but work just as well for the XDM1041

author: kwass
author_rank: Frequent Contributor
timestamp: July 01, 2022, 07:45:48 pm
content: I figured out a lot of the calibration process:Enter calibration as specified about: Utility, Math, Up, Range, Down, Debug (softkey)Pick the function and range you want to calibrate, each range has it's own calibration values stored.Toggle between the "zero" and the "coef" number (on the display) using the Range keyMove to the digit you want to change with the Dual key -- it always moves the cursor left to right but will cycle around.Use the Up and Down arrow keys to increase/decrease the value, it will roll over/under the higher order digit.You can calibrate the range to any value that you feed into the meter, it need not be the full scale value, 5.0000 volts for example. If you want to use 5.0000 volts then you can short cut this process and just hit the Run/Stop button.Exit calibration mode and save you settings at any time by hitting the Math key (not the Dual key as it says above).I was able to calibrate all ranges for all functions doing this. However the capacitance ranges are sort of funky, but still work ok. In all cases I set the "zero" number to all zeros. I have no idea if that's right or not, but my meter is very accurate now, much better than it was from the factory. I calibrated against a Fluke 8846A.

author: UniSoft
author_rank: Frequent Contributor
timestamp: July 01, 2022, 09:31:12 pm
content: Quote from: theHWcave on July 01, 2022, 08:06:32 amI guess that. That's why I never run it...By the way, did you try to contact support to request for the new version of firmware?I tried many time, but they no even replyDoes anyone know which TFT display they use?I was looking for it but did not find with such a pinout.D0...D7 - 8-bit DataPB10 - CLK (Clock)PB2 - DC (Data/Command)PB1 - CS (Chip Select)

author: theHWcave
author_rank: Regular Contributor
timestamp: July 02, 2022, 04:44:11 pm
content: Quote from: UniSoft on July 01, 2022, 09:31:12 pmOh, I was literally pounding continuously on OWON's door for a firmware update. Twice they sent me the same one I already gotand published on my Github page (May 2021). Finally, they said asking again is no use because they made a newer version of the meter and new firmware is only compatible with the newer hardware. Thank you, OWON for abandoning your initial customers ...

author: Markus2801A
author_rank: Regular Contributor
timestamp: July 03, 2022, 06:55:08 am
content: Quote from: theHWcave on July 02, 2022, 04:44:11 pmVery interesting, It would also be nice to know what exactly they mean with "newer version". A new hardware revision? or will there be the Version 2.0 of the XDM 1041, or did they mean the new battery powered XDM 1241?

author: theHWcave
author_rank: Regular Contributor
timestamp: July 03, 2022, 09:45:56 am
content: Quote from: Markus2801A on July 03, 2022, 06:55:08 amQuote from OWON: 26-Feb-2022: Our engineer said the V3.0 is for different hardware version but all functions are the same to your 2.0 , we don't have any new firmware.My response: What are the difference between my unit and the newer unit?Answer from OWON 28-Feb-2022: Using different LCD panel but has the same function

author: Fungus
author_rank: Super Contributor
timestamp: July 03, 2022, 12:22:15 pm
content: Quote from: theHWcave on July 03, 2022, 09:45:56 amA lot of manufacturers are being forced to change components with all the supply problems going on right now.

author: rsjsouza
author_rank: Super Contributor
timestamp: July 04, 2022, 01:09:37 am
content: Not only that, but they reserve the right to change their designs without prior notice... Leaving their customers behind with bugs does not build confidence and taints the track record, but Owon might not give a second thought to this, unfortunately.

author: fmolinelli
author_rank: Newbie
timestamp: July 16, 2022, 05:20:42 pm
content: Hi I ordered OWON XDM1241 from Banggood and I ogt it in 10 days!The new unit shows FW VER 3.3.1 and its SCPI commands are the same as the one reported by TheHWCave, with some sligth difference and... a bug (CONT and DIODE function selection are somehow exchanged in meaning; CONF:DIOD put it in DIOD but FUNC? returns CONT; CONF:CONT put it in CONT but FUNC? returns DIOD)Meanwhile I wrote a config file for TestControllerUA program, so I can get full automated controll of the DMM and gather/store/plot values (only the main function, not the secondary one... I'm tryiing to get it done!) and I can correlate irt with other bench devices:https://lygte-info.dk/project/TestControllerIntro%20UK.htmlI think it can be easily adapted for XDM1041 ... with some variations due to SCPI implementation!I'll share it if someone wants to try it!Many thanks to all EEVBlog contributors, TheHWCave among them, who inspired me!

author: davebb
author_rank: Frequent Contributor
timestamp: August 06, 2022, 02:37:18 pm
content: Quote from: sigxcpu on June 23, 2022, 01:02:48 pmDiode/continuity was broken (showing 0 and beeping continuously, Hi I have been getting this on my meter, i have not updated the firmware, i was thinking it was a relay sticking so i changed them, as it did not do this all of the time, some times i restarted the meter and it still did it, i have a nice fluke so i have not used this meter much or had it plugged in to the mains, yesterday i decided to try and get the AMP scale to Beter calibration to my fluke meter, i used my adjustable load and fist put some more solder on the 10a shunt to see were the reading was going then just used some wick and took a tiny bit of solder of at a time and got it to read within 0.4ma at 1amp and at 10Amp it was reading the same as my fluke,i have now restarted the meter a good few times and the Diode/continuity problem has not come back, do you think it is the firmware just not booting correctly, would it be wise to try and load a different firmware, My firmware version 1.3.0Thanks Dave

author: Kleinstein
author_rank: Super Contributor
timestamp: August 06, 2022, 03:23:56 pm
content: For the diode / continuity test one could check if there is a test-current flowing. So use a 2nd meter to measure that current (typical some 0.1- 1 mA depending on the meter).The diodes testing is relatively similar (mainly showing the result different) to the lower ohms modes, so this may also be effected and wirth a test.I would not expect a relay failure, more like a bad solder joint or PTC. If the ohms modes work and current is flowing it may be a software problem / cal constant set to zero.

author: davebb
author_rank: Frequent Contributor
timestamp: August 07, 2022, 08:52:23 pm
content: Hi if it was a bad PTC would it not do it all of the time ?anyway i have switched it on and off a lot the last 2 days and i can not get it to do this, at the moment it is all ok, if it goes again i will open it up and try and do some more testing,Thanks for your Help,Dave

author: javican
author_rank: Newbie
timestamp: August 22, 2022, 05:07:20 pm
content: I just purchased this on Ali and waiting for it to be delivered, I understand the are still a lot of issues so I'm up for the ride!!!

author: bffargo
author_rank: Regular Contributor
timestamp: August 30, 2022, 11:38:27 pm
content: Quote from: javican on August 22, 2022, 05:07:20 pmI just did as well, couldn't pass up a $103 super low price + stackable $9 off $90 and $15 off $100; netting it for $79 ish + tax USD. But will see in a month after it arrives.I am hoping that like the Riden RD6006 power supply, the firmware magicians can make this into something worth much, much more.I went with the USB instead of DB9, hoping that will be the best for any future interfacing.

author: Alexel
author_rank: Newbie
timestamp: September 05, 2022, 09:58:49 pm
content: Hi guys.Today I received my XDM1041. It contained firmware V3.6.0.I read the calibration table, maybe someone will need it.Does anyone have an OpenOCD built for Win x64 with C_DEBUGEN disabled? I want to read the full firmware, but so far there is only a computer with windows.

author: UniSoft
author_rank: Frequent Contributor
timestamp: September 06, 2022, 09:06:41 am
content: Quote from: Alexel on September 05, 2022, 09:58:49 pmThis is probably the hardware version not the firmware...The firmware just displays the string from the calibration data...There is no way to determine the OS version.Quote from: Alexel on September 05, 2022, 09:58:49 pmThis is not only calibration, as well some configuration, version, serial number, etc...Quote from: Alexel on September 05, 2022, 09:58:49 pmDon't spend time.This MCU (Cortex-M4) doesn't have that vulnerability.

author: pd9mwo
author_rank: Newbie
timestamp: September 06, 2022, 12:56:00 pm
content: any ext.ref mod available ??thx

author: Alexel
author_rank: Newbie
timestamp: September 06, 2022, 02:49:16 pm
content: Quote from: UniSoft on September 06, 2022, 09:06:41 amMaybe you're right, but the PCB is marked "YW:2228", while the serial number includes this value - SN:22280222... Maybe the hardware version is included in the serial number?Quote from: UniSoft on September 06, 2022, 09:06:41 amYes, you are right, I did not pay attention to the fact that the chip marking is GD32F303, not GD32F103...At the same time, ST-Link reads the chip ID as 0x414, which corresponds to F103, and it would be logical to get 0x422 from our chip (This ID for STM32F303xB/C and STM32F358 devices).

author: bffargo
author_rank: Regular Contributor
timestamp: September 15, 2022, 01:23:36 am
content: Quote from: Alexel on September 05, 2022, 09:58:49 pmQuote from: bffargo on August 30, 2022, 11:38:27 pmI got mine yesterday. Even newer than Alexel's. AliExpress seller came through, 17 day shipping to U.S. with all the discounts, no hassle/claims of increased prices/etc.. that other sellers pull. Net cost $79+tax. Very happy.

author: bffargo
author_rank: Regular Contributor
timestamp: October 17, 2022, 12:54:42 am
content: Did some testing with a 1041 seeing how easy it would be to hack it into a 1241 with only a couple inexpensive parts.The internal mains AC->DC power supply is labeled as 5VDC@2A. Actual power consumption measured by feeding in 5VDC from bench supply directly into the output pins of the built in one (not removing it from circuit) are as follows with screen brightness at 25%Standby: 6.15mABoot: 160mARun (VDC mode): 100mAI didn't test any other modesThe mains ground pin is connected all the way through on the negative power rail up until it connects to the meter board at which point it is isolated from the front inputs.It seems a bypass switch (/ hard power off), a USB>LiIon>500ma(to 2A) charge+inverter board and a decent 18650 should be enough to keep it powered for about 10 hours for little cost and lots of room to put it in the back with the mains board removed.

author: piit79
author_rank: Newbie
timestamp: November 14, 2022, 09:55:12 pm
content: Quote from: UniSoft on April 13, 2022, 06:53:38 pmI wanted to share my solution for this issue. Because the simplest one is obviously to replace a tiny 8-bit MCU with a 32-bit dual-core Arm MCU (RP2040) with 2 MB of flash and program it in (Circuit)Python, right?Anyway, I achieved my goal - now the startup is on single press while the shutdown has a short (~500 ms) delay.I wanted to re-program the ATtiny202, but I'd have to make a programmer first and I didn't even find the recommended CH340 serial adapter in my junk box. Might still do that later. The program is literally a few lines of code - not sure if there's anything else happening on the MCU, but the startup is controlled by a single I/O pin (PA1; HIGH - DMM starts slowly / LOW - DMM shuts down immediately). The power button is on PA2. I cut the trace going from the power button to the ATtiny202.The DMM doesn't start all that much faster as there's still a significant delay somewhere down the line, but I like that I can just press the button and know it will start.

author: mwb1100
author_rank: Frequent Contributor
timestamp: November 15, 2022, 09:46:16 pm
content: Quote from: Alexel on September 06, 2022, 02:49:16 pmSorry for responding to an oldish post. I think the reason for the ID behavior you're seeing is that the GD32F303 is much more like the STM32F103 than the STM32F303. GD32F303 is basically an STM32F103 clone with a Cortex-M4 instead of a Cortex-M3. The peripheral devices are clones of the STM32F103 peripherals (same register addresses).

author: ass20
author_rank: Regular Contributor
timestamp: November 27, 2022, 09:06:21 am
content: hiAbout versionsversion 2.xx have cpu stm32f103 (cortex m3) or cloneversion 3.xx have cpu GD32f303 (cortex m4)

author: gsmart
author_rank: Newbie
timestamp: November 27, 2022, 10:35:25 pm
content: Hi dave, i wrote because the same situation as now on my device, different not read at all i have used 4 times now diode is beeping not read volts, and not read resistance at all, fw are 3.1.0 have try to default conf reset but nothing still problem contacted owon with no response and aliexpress buyer protection is 15 dayvideo attacchmentThanks for now i hope some one have resolved this issue...

author: John+audio
author_rank: Newbie
timestamp: December 10, 2022, 01:20:26 pm
content: Farnell in the UK have just added this product to their portfolio of test equipment under the 'MULTICOMP PRO' brand name.https://uk.farnell.com/multicomp-pro/mp730889/dmm-bench-10a-1kv-50mohm/dp/3972198?MER=TARG-MER-PLP-RECO-STM71233-2£114.07 plus VAT

author: bffargo
author_rank: Regular Contributor
timestamp: January 02, 2023, 10:25:03 pm
content: Quote from: bffargo on October 17, 2022, 12:54:42 amUpdate: I finally hacked mine, and found out it doesn't need a full 5VDC into the logic board. It gets by just fine with direct LiIon 3.x volt output and doesn't need to be boost converted back up to 5V as per the original AC>DC converter in it.I used a tiny micro usb battery charger and a 18650 cell and connected that up to the AC>DC board, then feeding its second output (that is always kept at the voltage of the LiIon charge when on battery alone or ~4.2V when connected to a 5V input.To my surprise it has been running fine at the lower voltage without issues. I presume it may be dropping to 3.3V or so anyway once on the logic board, but didn't go poking around to verify.I thought I'd share for anyone else that wants to do a quick hack of the AC powered one into a 18650 powered version. Just need a couple 5 pin male XH2.54 male header pins and a 5 pin female plug with just 2 wires for voltage and you can bypass the feed through to the serial port then and connect up the battery/charge chip.I didn't take a picture of my mod, but here is a quick drawing.

author: luma
author_rank: Regular Contributor
timestamp: March 16, 2023, 02:54:52 pm
content: I've designed a couple 3D printed solutions to mount the XDM1041/XDM1241 for a few use cases.Here's a modelforGridfinitywhich lets you mount the meter to a base plate and then stack that into existing gridfinity solutions. Check the video link below for a fantastic presentation of the Gridfinity system, it's really well thought out and great for electronics workspace organization.Here's a modelfor theDDD Wall Control project(this one is my own project). This system utilizes steel Wall Control pegboards to mount tools etc securely to a wall. Parts are printed and press-fit like legos to create modular organization solutions for wall mounting.Gridfinity explanation (entertaining as hell, worth a watch)

author: robdejonge
author_rank: Regular Contributor
timestamp: March 27, 2023, 06:29:22 am
content: Does the new firmware or new device version (1241) still have the odd mV/V range situation?

author: dreiscal
author_rank: Newbie
timestamp: May 18, 2023, 03:09:05 pm
content: Quote from: UniSoft on July 01, 2022, 09:31:12 pmAny luck finding the display partnumber?Mine got damaged and I cannot find a replacement anywhere.

author: UniSoft
author_rank: Frequent Contributor
timestamp: May 20, 2023, 09:31:12 pm
content: Quote from: dreiscal on May 18, 2023, 03:09:05 pmNo luck...

author: diogoc
author_rank: Contributor
timestamp: June 05, 2023, 10:59:54 pm
content: Received my XDM1041 today.It have version 4.0.0For now I dont see big issues, all works fine including the software and datalogging export.I would like only to have the possibility of saving the speed mode.Regarding the hardware I liked that they used two large ceramic fuses.There are some small changes in the pcbs but the schematic seems the same.In the mcu board they changed the LDO to a switching regulator.

author: atat
author_rank: Newbie
timestamp: July 18, 2023, 01:33:38 pm
content: Downloading recorded data...one of XDM1041's (useless?) features is the possibility to record up to 1000 data points. The list can't be examined while recording is going on (why???) and every new recording erases the data already collected (in auto mode).No scpi commands are documented, otherwise known or appear obvious by looking at the firmware that allow the export of the recorded data. As far as I can tell, this is impossible with current firmware.However, every now an then, someone states that he or she had downloaded the recorded data (presumably using DMMEasyControl) - as opposed to logging a new set on the PC. Can any of these persons step forward and confirm their successful download?In that case, I'd be very interested in tracing the scpi commands used.

author: diogoc
author_rank: Contributor
timestamp: July 18, 2023, 02:07:29 pm
content: At least in version 4.0.0 it is possible do download the recorded data using using DMMEasyControl.This repository have the list of scpi commands:https://github.com/TheHWcave/OWON-XDM1041/tree/mainHowever, none is documented for downloading the datalog.You can try to trace the commands used by DMMEasyControl.

author: vk3em
author_rank: Contributor
timestamp: August 19, 2023, 01:56:24 am
content: Just bought one from Amazon which had the best price I could find in AU $159 AUDhttps://www.amazon.com.au/dp/B0BCFS1JHR

author: oxygen
author_rank: Newbie
timestamp: November 10, 2023, 10:15:33 am
content: I ordered XDM1241 from aliexpress and came from Czech .Opened it. There was TWO 18650 2200mAh cells in parallel.Taped in cell holder, but the tape was not stick good from one side ant cells was almost fallen out. One does not make contact, the other did.2325 is Year/week code.Consumption from USB-C without cells installed is about 300mA.Does anyone measure charging current so far?Edit: charging current about 1.6A (rough) for both batteries totalBatteries are quite different as capacity. Could be thah on was out of socket, or just cheapest cells.Purchased 2 Panasonic NCR18650B for replacementAttached few initial photos.

author: EM84
author_rank: Newbie
timestamp: November 11, 2023, 08:25:40 pm
content: Just sniffed the communication while DMMEasyControl downloads recorded data from an xdm1041. It is a simple (undocumented) SCPI command, it spills out a comma separated list of the table values:int:record?

author: oxygen
author_rank: Newbie
timestamp: November 23, 2023, 05:55:59 pm
content: Can measure temp with K thermocouple. Can show current temp, min, max and mV on screen in the same time.Nice

author: masta_k74
author_rank: Regular Contributor
timestamp: November 27, 2023, 06:26:10 am
content: @bffargoYou could also simply connect a shottky diode from the USB 5V pin to the output of the power supply unit. Then you could supply the device via the USB port. According to your tests, the few hundred millivolts lost at the shottky should not be a problem. The power consumption is also low enough not to cause any problems when connected to a PC. An ordinary power bank, which I'm sure almost everyone has lying around, would be a good idea.That's what I'm going to do. It can't hurt to have an optional power supply.

author: ionut22
author_rank: Newbie
timestamp: January 09, 2024, 08:03:04 pm
content: Hello,Somebody can help me with calibration file for version V4.1? I pressed auto calibration button from hidden menu and after that i find this topic!Thankyou!

author: Proxy64
author_rank: Regular Contributor
timestamp: February 05, 2024, 01:50:58 pm
content: I just got mine, version 4.2Is there an app running on Macos ?

author: MF-jockey
author_rank: Regular Contributor
timestamp: June 14, 2024, 10:43:08 pm
content: My OWON XDM1241 arrived today, it is also version V4.2.0.I measured the current consumption directly on the batteryThe quiescent current of 1.074 mA was shocking. This means that within half a year the fully charged batteries (2x approx. 2000mAh = 4000 mAh) are completely discharged. So you have to make sure to charge the device regularly every three months.In operation, the current consumption is highly dependent on the display lighting: 0%=78mA, 25%=112mA, 50%=144mA, 75%=175mA, 100%=202mA.On my reference voltage source 5 V, the XDM1241 shows 4.9994 VDC. The reference was measured by the supplier in November 2019 at 5,000.37 V, I cannot judge the current accuracy.At the reference 10 V (specified as 10,000.66 V) 9.996-9.997 VDC are displayed, in the 500 V range exactly 10.00 VDC.The brightness of the display and the connection of the power supply (USB) have no influence on the measured values.

author: ClubFoto
author_rank: Newbie
timestamp: August 29, 2024, 09:13:20 am
content: I have been working with XDM1241 version 4.2 for a few months and I have found that the capacitor measurements are wrong and in other cases it indicates out of scale, with values ​​that should read correctly.I have tried to calibrate using the method explained in the thread, but I cannot find the appropriate values.Can you tell me if this model can be reset to factory settings, use an automatic calibration or, failing that, what values ​​to use to calibrate the capacitors.

author: ClubFoto
author_rank: Newbie
timestamp: August 29, 2024, 05:53:31 pm
content: How is the calibration file generated?Could you please tell me the values ​​that appear in the capacitor calibration?

author: RogerG
author_rank: Regular Contributor
timestamp: November 14, 2024, 10:48:13 am
content: Hi,I own a XDM1241 since a few months and just added a k-type thermocouple to it.The readings are 6°C too low with cold DMM and are increasing by in a step of 3°C after 10minutes and another step of 1°C after half an hour. It's really weird since my handheld DMM reads the correct 21°C from start and stays constant.Is there a way to get better temp readings with the XDM?RegardsRoger

author: Kleinstein
author_rank: Super Contributor
timestamp: November 14, 2024, 01:46:18 pm
content: The problem is likely the position of the cold junction sensor. With the banana plugs the correct position would be at the TC to plug and is thus not accessible. Any measuremen inside the meter is only a crude guess. These sensors are limited no matter what the meter does.So there is likely nothing on can do. The bench meters naturally have more self heating and difference from cold to warmed up state. A handheld meter is more made for low power und thus less warm up.

author: ua3vtm
author_rank: Newbie
timestamp: February 07, 2025, 04:40:37 pm
content: All good! Tell me the firmware for 1041 with Russian. Thank you.

author: coromonadalix
author_rank: Super Contributor
timestamp: February 07, 2025, 05:31:06 pm
content: alas this pseudo dmm bench meter is based on handheld icon hy3131 chipset, i would say not to expect much out of themyou would need to compare with the eevblog meter who has the same chipset the gw121 if i recall ??as written by kleinstein, the box shape and space could interfere with stability, warmup time etc ... still they have some quircks in the FW to iron out

author: djtaotao
author_rank: Newbie
timestamp: March 19, 2025, 01:44:06 pm
content: Hello,can somebody take a close-up picture for this component or post the marking?

author: bebopdk
author_rank: Contributor
timestamp: March 19, 2025, 07:39:52 pm
content: Probably a SRV05-4 esd protection diode, take a look at this CH340 data sheet, there it is also mounted on the USB inputs as in the picture:https://www.sunrom.com/p/ch340g-soic16-usb-to-serial-ttl-uart-ic

author: bffargo
author_rank: Regular Contributor
timestamp: April 12, 2025, 02:00:38 am
content: A clone of the original XDM1041 has appeared as the Victor 8045Mhttps://www.aliexpress.us/item/3256806713850862.htmlVideo:Looks like v4.2.0 firmware. From other videos, apparently those of us that got the earlier 1.2.0 versions, the newer firmware is not compatible as they changed the screen. Probably why they have no downloads for years, only the random github site with the 20210525 version.

author: illiac4
author_rank: Regular Contributor
timestamp: April 28, 2025, 05:21:31 am
content: https://github.com/markusdd/rusty_meter

author: Elektroarzt
author_rank: Newbie
timestamp: May 13, 2025, 03:56:12 pm
content: After I was a bit annoyed by the fact that the XDM1041 starts in low sampling mode, I had the idea to have an ESP32 automatically set the sampling mode to high via SCPI after starting. During the development I came up with the idea of integrating the multimeter into my home automation via WiFi/MQTT in Node Red. The prototype runs reliably, a simple circuit board is on the way. The MQTT Bridge PCB replaces the original USB board and is supplied by 5V of the XDM1041. It can be easily changed from USB to WiFi/MQTT and back. If there is enough interest in the community, I am happy to share hardware and firmware on GitHub.

author: ironcurtain
author_rank: Regular Contributor
timestamp: May 18, 2025, 10:26:35 am
content: Trying to run DMMEasyControl, as soon as I click on Connect the program closes (no crash).I have other NI Visa and instruments connected (and I can't remove them just to use the application, I need to do concurrent monitoring using multiple instruments).Anyone else had this problem?For now I will settle with being able to record a time series of a temperature probe reading.

author: wtfrules
author_rank: Newbie
timestamp: July 24, 2025, 10:46:31 pm
content: Try thishttps://github.com/markusdd/rusty_meterIt was posted in this thread by someone else

author: wtfrules
author_rank: Newbie
timestamp: July 26, 2025, 12:57:58 am
content: Hi Y´all,I´ve got this multimeter two weeks ago, and so far so good.What´s driving me crazy is to find a way to storage or save minor settings, like in diode mode, when the device is freshly turned on, I´ve to change the thresgold in diode mode for beeping instead at 0.5V to 0.1V or in resistance mode to change the aquisition from slow to fast? I´ve to do these mods every time the unit is power on.My XDM1241 have firmware 4.3.0Anyone know if this is posible?Thanks in advanceHave a good one!

author: Elektroarzt
author_rank: Newbie
timestamp: July 26, 2025, 05:20:18 am
content: That was exactly my issue too! That’s why I use an ESP32 to switch from Slow to Fast Acquisition Mode right after starting via SCPI. You could use the PCB to set fixed settings after each start (like diode mode). Or you could make a backup of the current settings and load them after booting, so that the last settings are always restored. This isn’t implemented yet, but I can provide the code so you can freely adjust it, if you like to tinker on that. Out of the box, the multimeter is not capable for that, from what I know.

author: wtfrules
author_rank: Newbie
timestamp: July 26, 2025, 07:28:20 pm
content: I was watching your previous post and looks promising! Now more promising after your clarification about the "mods" via SCPI!I would like to test it and give it a try, if you can share would be nice!Thanks!

author: Elektroarzt
author_rank: Newbie
timestamp: July 26, 2025, 10:30:30 pm
content: Give me some days for setting up the repo. If you like to contribute to the project, you’re welcome. At the moment the software is vibe coded with GPT o4-mini-high in Micropython. I’m open for changes.

author: Elektroarzt
author_rank: Newbie
timestamp: July 27, 2025, 12:41:33 pm
content: Ok, upload is done. You can find the sources underhttps://github.com/Elektroarzt/owon-xdm-remote

author: wtfrules
author_rank: Newbie
timestamp: July 27, 2025, 07:38:43 pm
content: Thanks!Looks amazing!I´ll gather things and test it ASAP and get backto you