New Brymen BM2257 Multimeter - Page 1
Forum section: electronics / testgear

author: EEVblog
author_rank: Unknown
timestamp: August 28, 2024, 06:43:24 am
content: Just found out about this through a Youtube comment.Basically a BM235 with AutoHold, Bargraph, and serial coms.US$127http://www.brymen.com/PD02BM2250_2257.htmlhttp://www.brymen.com/images/ProductsList/BM2250_List/BM2250-manual-Print1-r3.pdf

author: Fungus
author_rank: Super Contributor
timestamp: August 28, 2024, 06:51:55 am
content: 96 Euros + Taxhttps://brymen.eu/shop/bm2257/

author: rsjsouza
author_rank: Super Contributor
timestamp: August 28, 2024, 08:37:23 am
content: That is one of the most featured (and well rounded) compact meter I have seen. It corrects three weaknesses of its cousin BM257: the autohold, the higher capacitance measurement of 10mF and a decent diode voltage measurement of 3V. The logic level takes a hit, at 200k @ 3V (the other is 500kHz @ 3V and 1MHz @ 5V).

author: Fungus
author_rank: Super Contributor
timestamp: August 28, 2024, 11:39:14 am
content: The four-function Ohms/Diode/Continuity/Capacitance range position is a bit of a turn off.Would it have killed them to add an extra click on the dial?

author: Furna
author_rank: Frequent Contributor
timestamp: August 28, 2024, 01:35:50 pm
content: It looks very promising but if it doesn't have a blue holster I won't buy it.Seriously, I was thinking about a low cost and compact meter while also "sponsor" somehow EEVblog so I was evaluating the blue BM235.

author: EEVblog
author_rank: Unknown
timestamp: August 29, 2024, 02:50:28 am
content: Quote from: Furna on August 28, 2024, 01:35:50 pmI've emailed Brymen...

author: ArdWar
author_rank: Frequent Contributor
timestamp: August 29, 2024, 03:00:38 am
content: Quote from: Fungus on August 28, 2024, 11:39:14 amFor double opposite contact you can't have more than 180° turn, and they probably don't want to change the already running 8-notch mold that they also use for many other models.

author: J-R
author_rank: Super Contributor
timestamp: August 29, 2024, 05:30:48 am
content: I wouldn't compare the BM225x models to the BM23x series, would be the BM25x series instead. So BM251 -> BM2251 and BM257 -> BM2257.On the BM25x they placed the EF function on the Hold button, which in hindsight was a strange choice. New models now have EF on the AC V selector position instead along with VFD, allowing for the logical return of AutoHold."Multitalented and Compact; Loaded with Nice Up-to-date Features!"The mV logic level Hz function is found on many of their other models. So nothing much new about that either.There are also the new BM280xCSE models:"This 2800 CSE meter series is a safety Category and EMI Shielding Enhanced (CSE)version of our popular 800 practical meter series. Apart from the added up-to-datefeatures and improvements in safety ratings, it is also equipped with EMI shielding onboth sides of the circuitry module to improve measurement stability under harshelectromagnetic interferences, especially in the electrical and automotive industries."

author: Furna
author_rank: Frequent Contributor
timestamp: August 29, 2024, 06:46:15 am
content: ... and due to the fact that last March I bought a BM869s you can expect soon a BM8869s ...I am joiking but I'd not be too much surprised

author: EEVblog
author_rank: Unknown
timestamp: August 29, 2024, 07:54:44 am
content: Quote from: EEVblog on August 29, 2024, 02:50:28 amI have the FOB price, it's not much more than the BM235...Hmm, what to do.Do I offer yet another meter, (with the new pocket one coming, that would be 5 meters), or do I phase out the BM235 and replace it with this at a slightly higher price?

author: electr_peter
author_rank: Unknown
timestamp: August 29, 2024, 08:12:59 am
content: I looked at BM2257 specs carefully - it is very similar and slightly better than BM235 in some aspects, but not in other aspects. Very similar meter overall, not sure if it worth extra price over BM235.Definitely do not offer both at once, as these models are very similar. Whether to replace or not, not sure, probably not for the same reasons.

author: J-R
author_rank: Super Contributor
timestamp: August 29, 2024, 08:14:26 am
content: Quote from: Furna on August 29, 2024, 06:46:15 amA BM2869s... There are some things they could improve slightly...Quote from: EEVblog on August 29, 2024, 07:54:44 amSo are they willing to let you brand the BM2257 as-is? Or would you drop a feature or two and get something like a BM2255?Seems like you'd have to insist on the blue-adjacent paper white backlight, though. Amber would clash with blue.

author: EEVblog
author_rank: Unknown
timestamp: August 29, 2024, 08:35:50 am
content: Quote from: electr_peter on August 29, 2024, 08:12:59 amAccuracy specs aren't really that important in this lecel of meter, they are all basically the same.In this case the BM2257 has AutoHold and bargraph like the BM786, plus serial.I could still offer the BM235 at a permanent discount and make less margin on it for those who are watching every dollar.

author: J-R
author_rank: Super Contributor
timestamp: August 29, 2024, 08:38:37 am
content: Quote from: electr_peter on August 29, 2024, 08:12:59 amComparing the features and specs of the BM235, BM257s and BM2257 it seems a lot of the BM2257 specs follow the BM235 while the physical layout is identical to the BM257s (but different from the BM235). Also, I see that the BM257s has the full blown AutoCheck feature where it automatically switches between "LoZ DCV, LoZ ACV & OHMS" while the BM235 and BM2257 are just AutoV.Also the BM2257 has the IR interface (as does the BM25x series).My opinion on these lower-end DMMs is that features are slightly more important than specs. The last digit is going to be +/- 2d or +/- 4d on top of the percent-of-reading spec.

author: Furna
author_rank: Frequent Contributor
timestamp: August 29, 2024, 10:45:29 am
content: Quote from: J-R on August 29, 2024, 08:14:26 amSure BM2869s ... I am not good at understanding how companies name their products series over the years.The only thing that comes to my mind missing on BM869s is the duty cycle for AC ... I really do not miss it; my BM869s sits on the bench and rarely touches AC.Sure WiFi ... but I am not a fun of WiFi. I am still over USB for DMMs.Quote from: EEVblog on August 29, 2024, 08:35:50 amI agree, accuracy IMHO is not a pillar for a small/cheap DMM ... I want something that I can bring easily with me and has as much features as possible.The feature of BM2257 I most appreciate is the bar-graph; Auto-hold convenient ... serial just a plus.I like the fact that EEVblog shop has only a few DMMs; I feel like an Electronic Engineer already made a selection on my behalf so I do not have to go through hundreds f pages trying to avoid stuff for electricians, automotive etc.For this reason I would like to see BM235 removed from the shop ... but I see Dave's point.So all in all he is right IMO; BM235 discounted and BM2257 offered as his successor.

author: EEVblog
author_rank: Unknown
timestamp: August 29, 2024, 12:26:07 pm
content: Quote from: Furna on August 29, 2024, 10:45:29 amMy new pocket meter is the 1980sQuoteI don't think the BM2257 will work unless I permanately discount the BM235Brymen are sending me a sample mid Sept. And they said they can do the same blue holster and rebranding without changing the model number.FYI, Brymen won't let me just pick any model number as it requires going through the UL certification again.

author: EEVblog
author_rank: Unknown
timestamp: August 29, 2024, 12:30:53 pm
content: Quote from: EEVblog on August 29, 2024, 08:35:50 amSo much so that I didn't even mention accuracy in my Beginner meter video I just released.

author: 2N3055
author_rank: Super Contributor
timestamp: August 29, 2024, 12:49:06 pm
content: Quote from: Furna on August 29, 2024, 10:45:29 amI can tell you what could be done for new gen 869:- Remembering preferences. I prefer meter to be quiet unless in continuity mode. You can do that, but EVERY single time you power it on. Just remember setup preferences.- AC coupling in AC mV mode. That is not a big deal, but a chance to make it better when redesigning.- Auto Hold. That is not important to me, but lot's of people- Diode beep ( a lá Fluke) is also something a lot's of people asked for.For me literally remembering preferences is only annoying thing about the meter. That shows you how good it is.

author: 0Anonym
author_rank: Newbie
timestamp: August 29, 2024, 12:52:19 pm
content: I have looked into getting a Quality meter over the past few Weeks and my choices where the BM235, the 257s and the 2257. I didn’t quite understand why I couldn’t find anything about the BM2257, but I didn’t know at the time that it was so new.That means I will have to wait a bit longer until the new EEVBlog edition comes out.

author: Furna
author_rank: Frequent Contributor
timestamp: August 29, 2024, 01:45:08 pm
content: Quote from: 2N3055 on August 29, 2024, 12:49:06 pmI see your point ... indeed it already remembers every function you set.QuoteNever had a Fluke so I not missing that featureQuoteAgree

author: Furna
author_rank: Frequent Contributor
timestamp: August 29, 2024, 02:03:09 pm
content: Quote from: EEVblog on August 29, 2024, 12:26:07 pmI am not so lucky; EE passion went Lo&Hi, moved apartment/house multiple times across different continents.The oldest meter I have is the MAS-345; I date it back to 2005-2006 but not sure.QuoteOK I took a note: part 2 of the Beginner meter video is scheduled for the end of last week of Sept and will feature a blue BM2257BTW I see no reason why you might want to change the model number

author: cv007
author_rank: Frequent Contributor
timestamp: August 29, 2024, 02:14:22 pm
content: Note the backlight time listed in the manual- 16 minutes. I was happy when I discovered my 857s had 256 seconds, which is better than others but sometimes still not long enough (I do like my 857s).

author: RFDx
author_rank: Regular Contributor
timestamp: August 29, 2024, 03:22:44 pm
content: What's the display backlight colour? On the EU website it shows a paper white backlight but in the datasheet it's amber.

author: HKJ
author_rank: Super Contributor
timestamp: August 29, 2024, 04:25:14 pm
content: Where it has a big advantage over BM235 is the computer connection. I often find it useful to link a meter to a computer and record data.

author: RAPo
author_rank: Super Contributor
timestamp: August 29, 2024, 05:29:20 pm
content: Currently, the BM2257 is out of stock.I received a mail from Brymen (Adrian Wieczorkowski) stating that it will be in stock again around 27 September.Then you can order it fromwww.brymen.eu.

author: 0Anonym
author_rank: Newbie
timestamp: August 29, 2024, 09:24:43 pm
content: Sorry if this is a stupid question, but would you guys choose the Gossen Metrawatt METRALINE DM62 over the BM 2257?

author: EEVblog
author_rank: Unknown
timestamp: August 29, 2024, 11:25:14 pm
content: Quote from: 0Anonym on August 29, 2024, 12:52:19 pmGiven that Brymen can't send me one for a few weeks means that it's not ready yet. Does anyone actually have stock? Wouldn't surprise me if there are delays. The original BM235 was something like 9 months late from when they promised. And the BM786 was delayed too.

author: EEVblog
author_rank: Unknown
timestamp: August 29, 2024, 11:27:51 pm
content: Quote from: 0Anonym on August 29, 2024, 09:24:43 pmSeems like a much bigger meter.The thing I like most about the BM235/257/2257 is that it's small, and it has big digits.

author: Fungus
author_rank: Super Contributor
timestamp: August 30, 2024, 02:26:02 am
content: Quote from: 0Anonym on August 29, 2024, 09:24:43 pmNo. It's much more expensiveandit's a horrible color.

author: 0Anonym
author_rank: Newbie
timestamp: August 30, 2024, 12:36:40 pm
content: Thanks for the responses.Can someone explain why some Multimeters have joined AC and DC switch Positions (for example the BM235) and some have split AC and DC switch Positions (like the BM2257)?To me it seems like, even though its only a very small detail, it seems like a simplification when working in a rush.

author: HKJ
author_rank: Super Contributor
timestamp: August 30, 2024, 04:08:07 pm
content: Quote from: 0Anonym on August 30, 2024, 12:36:40 pmIt a design decision, there is a certain number of modes that a meter has and they must be distributed over a number of switch positions. Some can be combined, others need a separate position. Then it is up to the designer how to distribute them, some prefer shared AC/DC (May not be possible on a good meter), some prefer to combine ohms/diode/cont. in a single position.

author: xKertx
author_rank: Regular Contributor
timestamp: August 30, 2024, 05:25:33 pm
content: Quote from: RFDx on August 29, 2024, 03:22:44 pmOn the brymen.com site it says "Warm Amber Backlight".

author: RFDx
author_rank: Regular Contributor
timestamp: September 03, 2024, 09:31:05 pm
content: Quote from: xKertx on August 30, 2024, 05:25:33 pmThanks. On brymen.eu it's displayed with a (paper)white backlight unless that's just a picture with the backlight turned off. The datasheet however shows the BM2257 with the "warm" amber backlight.

author: Furna
author_rank: Frequent Contributor
timestamp: September 03, 2024, 10:09:57 pm
content: Quote from: EEVblog on August 29, 2024, 11:25:14 pmThe polishdistributorbrymen.eu listed it as available for a few days ... currently it is not possible to order it.Official distributors Welectron and Eleshop do not list at all.I guess we can expect some delays and probably your sample could be one of the first.

author: EEVblog
author_rank: Unknown
timestamp: September 04, 2024, 01:23:43 am
content: Quote from: Furna on September 03, 2024, 10:09:57 pmI assume I'm getting the first production batch run.I wonder if it will have a firmware programming port like the BM786 has?

author: 0Anonym
author_rank: Newbie
timestamp: September 07, 2024, 08:34:06 pm
content: Does it make any sense to contact the Polish reseller even though someone else from the forum contacted them before or is Brymen known for not sharing Information in advance?

author: Furna
author_rank: Frequent Contributor
timestamp: September 07, 2024, 08:55:35 pm
content: Quote from: 0Anonym on September 07, 2024, 08:34:06 pmWhat inforamtion are you looking for?Why buy from a Polish reseller/distributor if you are German and there are reseelrs/distributots in your own country?I guess every reseller/distributor will anser you ...

author: EEVblog
author_rank: Unknown
timestamp: September 12, 2024, 05:13:58 am
content: Got it!Orange backlight is very nice, as is the very fine bargraph.I note that CATII marking is missing as per the new standard.

author: J-R
author_rank: Super Contributor
timestamp: September 12, 2024, 05:40:15 am
content: What does it look like without the backlight on? Just a white LCD?Are they able to offer it with the paper-white backlight or just the amber?

author: EEVblog
author_rank: Unknown
timestamp: September 12, 2024, 06:27:49 am
content: Quote from: J-R on September 12, 2024, 05:40:15 amSame transflective sceen as the BM235. BM235 is slightly better at higher angles.Haven't asked about backlight.

author: nidlaX
author_rank: Frequent Contributor
timestamp: September 12, 2024, 06:47:33 am
content: EEVblog BM2257 waiting room

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 12, 2024, 06:52:37 am
content: Am I the only one bothered by the A <-> mA inversion?

author: J-R
author_rank: Super Contributor
timestamp: September 12, 2024, 06:58:59 am
content: Quote from: Ice-Tea on September 12, 2024, 06:52:37 amWell, the 2257 is basically a newer 257, so in that regard the jacks haven't moved.Also, the BM78x series has this arrangement, so it's probably their current standard.

author: EEVblog
author_rank: Unknown
timestamp: September 12, 2024, 07:08:48 am
content: Quote from: Ice-Tea on September 12, 2024, 06:52:37 amTeardown might be interesting...

author: Ice-Tea
author_rank: Super Contributor
timestamp: September 12, 2024, 07:26:26 am
content: Quote from: J-R on September 12, 2024, 06:58:59 amStill bothered

author: tautech
author_rank: Super Contributor
timestamp: September 12, 2024, 07:33:16 am
content: Quote from: Ice-Tea on September 12, 2024, 06:52:37 amYeah it's 100% dumb on the same class of DMM.The world is already confusing enuf......

author: J-R
author_rank: Super Contributor
timestamp: September 12, 2024, 07:52:31 am
content: Quote from: tautech on September 12, 2024, 07:33:16 amTalk about confusing; for the third time, the 2257 is based on the 257, not the 235, so there are no jack changes as you can see from this review 12 years ago:https://www.eevblog.com/forum/testgear/brymen-bm-257-pictures-and-mini-review/

author: robert.rozee
author_rank: Frequent Contributor
timestamp: September 12, 2024, 08:20:39 am
content: Quote from: J-R on September 12, 2024, 07:52:31 ambut is the 257 not based on the 235? or is the 235 based on the 257? or is there some other intermediate model that we have not seen yet that links them all together?cheers,rob :-)

author: shapirus
author_rank: Super Contributor
timestamp: September 12, 2024, 08:29:21 am
content: Quote from: J-R on August 29, 2024, 08:14:26 amYeah definitely. I want a BM869s with auto hold, LowZ voltmeter, maybe faster autoranging and 60k counts, beep in diode mode if the diode is shorted, and... and... I guess that's all: unfortunately, the BM869s is good enough as it is, there's not much to improve upon.

author: Furna
author_rank: Frequent Contributor
timestamp: September 12, 2024, 08:41:33 am
content: Quote from: EEVblog on September 12, 2024, 07:08:48 amDefinitely!

author: EEVblog
author_rank: Unknown
timestamp: September 12, 2024, 09:19:07 am
content: Quote from: robert.rozee on September 12, 2024, 08:20:39 amThe BM235 came after the BM257.I wanted to sell the orignal BM257 but they said no, and to wait for the BM235 they were working on, which took about a year BTW.

author: J-R
author_rank: Super Contributor
timestamp: September 13, 2024, 12:37:53 am
content: A thought on the jack placement:If you line up all of the Brymen DMMs you can see that they really only have to keep track of a handful of building blocks: enclosures, PCBs, jacks, LCDs, etc. And I'm confident the final assembly is done by hand. So it's trivial to add another product to their lineup because they just need to spray the top cover a little differently, apply different stickers and have the pick/place machine add or remove components as the PCB goes by. Then it's all brought together for assembly/calibration/etc. They don't have to place an order for a million units and hope they sell over the next 5 years; they can make just enough for that quarter's demands.To bring that paragraph together, I think they are always going to be adding new products on a regular basis to cover even the furthest corners of the market. There are probably just as many people who insist on having the A jack next to common as there are people who want mAuA next to common.Looking back through DMM design, it seems a lot of them don't have a mA jack at all, only A - COM - V, in that order. So when a designer was initially adding mAuA they probably placed to the side to avoid offending existing users. Eventually, designs came out with the order changed to what is maybe a more common arrangement of A -mAuA - COM - V, of which Fluke and Brymen's high-end DMMs currently follow.Ultimately, test equipment is SO different, it's never going to be realistic to standardize on this or even things like selector switch order. You always need to think before you leap...

author: EEVblog
author_rank: Unknown
timestamp: September 13, 2024, 02:29:10 am
content: Quote from: J-R on September 13, 2024, 12:37:53 amBrymen don't even do that, theynevercarry excess stock. They literally make to order, and there is at least a two month lead time on all orders. Dealers like myself have to plan ahead and work around this.Many times I have forgotten this and been left without stock for months.

author: EEVblog
author_rank: Unknown
timestamp: September 13, 2024, 06:46:32 am
content: Teardown photos:https://www.flickr.com/photos/eevblog/albums/72177720320285816

author: Fungus
author_rank: Super Contributor
timestamp: September 13, 2024, 08:32:47 am
content: What's with all the wires?

author: EEVblog
author_rank: Unknown
timestamp: September 13, 2024, 08:47:20 am
content: Quote from: Fungus on September 13, 2024, 08:32:47 amPCB routing constraints I would presume. Probably compliance reasons forcing a certain layout and they have to work around that.

author: Furna
author_rank: Frequent Contributor
timestamp: September 13, 2024, 09:47:15 am
content: Quote from: EEVblog on September 13, 2024, 08:47:20 amCompliance with?I have the idea that the more cables you put in a DMM the less compliant with anything.From the functionality perspective I do not really care; if it measures within specs I am fine.

author: EEVblog
author_rank: Unknown
timestamp: September 14, 2024, 06:53:46 am
content: Quote from: Furna on September 13, 2024, 09:47:15 amThe various CAT requirements and the Low Voltage Directive (LVD) 2006/95/EC etcFor example, my new 1980s pocket meter from Sanwa has just had to have some PCB changes in terms of creepage distances due to the LVD requirements.

author: floobydust
author_rank: Super Contributor
timestamp: September 15, 2024, 04:37:39 pm
content: Quote from: EEVblog on September 13, 2024, 06:46:32 amFrom the pic, confirm the ferrite bead L4 is actually soldered, it looks bad. Likely for current measurement function.No offense Dave but Brymen still has poor PCB design. El crapola footprints the wrong size, as always. I think they are better with this board but there is a limit as to how oversized a footprint can be. No idea why a bunch of traces have removed soldermask on them. Hint: not a guard-band lol.

author: EEVblog
author_rank: Unknown
timestamp: September 15, 2024, 10:34:10 pm
content: Quote from: floobydust on September 15, 2024, 04:37:39 pmJoint looks fine from that photo, the pad likley extends under the component.

author: blue_lateral
author_rank: Contributor
timestamp: September 16, 2024, 05:41:16 am
content: Quote from: EEVblog on August 29, 2024, 07:54:44 amQuote from: EEVblog on August 29, 2024, 12:26:07 pmQuote from: EEVblog on September 14, 2024, 06:53:46 amI've googled the crap out of this and got nowhere. I gather there is a new EEVblog pocket meter in the works? The only references I can find are to a Sanwa pocket meter from about 6 years ago that is no longer in the store. I'm just curious. Is there a thread somewhere?

author: EEVblog
author_rank: Unknown
timestamp: September 16, 2024, 06:27:04 am
content: Quote from: blue_lateral on September 16, 2024, 05:41:16 amNo thread. It's my own branded updated version of the PM3

author: J-R
author_rank: Super Contributor
timestamp: September 22, 2024, 09:51:01 pm
content: Quote from: EEVblog on September 16, 2024, 06:27:04 amHave you considered branding these Sanwa kits:https://overseas.sanwa-meter.co.jp/products/teaching_materials/kit-8d.htmlhttps://overseas.sanwa-meter.co.jp/products/teaching_materials/pc20tk.html

author: EEVblog
author_rank: Unknown
timestamp: September 23, 2024, 02:01:58 am
content: Quote from: J-R on September 22, 2024, 09:51:01 pmInteresting. Didn't know they had kits.Don't know why they have the DCV adjust pot, that seems kinda dumb from a practicality point of view.The one problem with Sanwa is that their FOB prices are not cheap.

author: Fungus
author_rank: Super Contributor
timestamp: September 23, 2024, 11:07:28 am
content: Quote from: EEVblog on September 23, 2024, 02:01:58 amI assume they aren't calibrated.

author: Kleinstein
author_rank: Super Contributor
timestamp: September 23, 2024, 03:24:29 pm
content: The PCB for the BM2257 looks a bit simpler (less chips) than the BM257. In the data sheet the AC frequency range is quite limited. I wonder if the meter uses some digital RMS internal to the DMM chip - still not mentioning the fast response typical for digital RMS.The input jack-PCB looks rather similar to the 257 version where I have found pictures. An update for additional slots and likely possible to fit the new version also to the 257 (or already used in later versions of the 257).

author: Fungus
author_rank: Super Contributor
timestamp: September 23, 2024, 04:30:44 pm
content: TRMS bandwidth isn't something I'd go out of my way for in a DMM these days.I'm sure a $25 FNIRSI oscilloscope can run rings aroundanyDMM when it comes to measuring AC over a couple of kHz, and 12-bit oscilloscopes are under $400.It's not the 1980s.

author: floobydust
author_rank: Super Contributor
timestamp: September 23, 2024, 06:22:26 pm
content: I won't use a low bit scope to measure ACmV when I'm looking for small dB losses. Love the 80's and multimeters good for over 1.5kHz when needed. The Sanwa kit and pocket meters are not true-RMS, 400Hz spec. as well.It's OK I'm not expecting the world in something low cost and compact. I'm more worried about them (Sanwa) passing the BBQ lighter test lol

author: EEVblog
author_rank: Unknown
timestamp: September 23, 2024, 11:58:19 pm
content: Quote from: Kleinstein on September 23, 2024, 03:24:29 pmYes, all the low end meters from every brand have on-chip true RMS conversion these days.

author: floobydust
author_rank: Super Contributor
timestamp: September 24, 2024, 04:00:44 am
content: I find the low-end multimeters are usually running 8-bit clunker MCU's with the true-RMS done as a H/W DSP section AC-coupled and good to around 1.5kHzNot sure what silicon-base Brymen is running in this BM2257 but AC freq. response seems to be 40-1,000Hz.Sanwa pocket multimeters using e.g. Fortune SemiconductorFS9721-LP3is just a basic rectifier 40-400Hz rated.

author: EEVblog
author_rank: Unknown
timestamp: September 24, 2024, 05:09:24 am
content: Quote from: floobydust on September 24, 2024, 04:00:44 amActually, a 32bit clunker, probably the same as in the 78x series, as they seemed to have switched from ROM based devices to flash now, so makes sense to standardise.

author: Kleinstein
author_rank: Super Contributor
timestamp: September 24, 2024, 10:05:48 am
content: For a modern DMM chip including digital RMS makes absolute sense. SD ADCs can work up to the audio range and the extra math to calculate the RMS result is not that much (e.g. can be done even with a 8 bit µC).The simple digital RMS is also not that bad. On the positive side They could also work ok close to zero, with correct subtraction of it's own noise. They can be fast responding and no issue with lower frequencies.The analog RMS chips have have to compromise between low frequency accuracy and response speed. Already the need to work well at mains frequency makes them a bit sluggish to respond. So accuracy usually drops, not much below 40 Hz.So both ways have there pros and cons and a good digital implementation can outperform the old style analog in most aspects. Fast sampling could still add a bit to the power consumption.Good higher frequency response would however also need compensation at the divider / input amplifier.Somwhere in the kHz range is a cross over from the resistive to capacitive divider part. With several taps the compensation may not be easy.So no need for the cheap RMS to work to much higher frequencies and limiting the frequency can reduce the noise.

author: EEVblog
author_rank: Unknown
timestamp: September 24, 2024, 10:13:12 am
content: Quote from: Kleinstein on September 24, 2024, 10:05:48 amThe interesting thing is the modern design Brymens don't even have a DMM chipset, it's just a micro with some analog functionality.

author: Fungus
author_rank: Super Contributor
timestamp: September 24, 2024, 01:04:11 pm
content: Quote from: EEVblog on September 24, 2024, 10:13:12 amIt's the logical next step.

author: mihaip
author_rank: Newbie
timestamp: October 09, 2024, 04:21:30 pm
content: Dave, thanks for all your work.Are you planning a review of this multimeter ?I'm quite interested in buying this instead of BM257s, but I want an expert opinion first.Regards

author: EEVblog
author_rank: Unknown
timestamp: October 09, 2024, 09:36:40 pm
content: Quote from: mihaip on October 09, 2024, 04:21:30 pmMaybe eventually, but if I'm going to sell it, then doesn't make sense to do a review unitl I have it in the store.I've been using it and I haven't found any issues. Worth the bit extra over the BM235 IMO.

author: Furna
author_rank: Frequent Contributor
timestamp: October 09, 2024, 09:39:37 pm
content: Quote from: EEVblog on October 09, 2024, 09:36:40 pmSo now the question is: when do you think to make a choice to sell it or not?Also are you aware when Brymen is releasing it on the market?Thank you

author: EEVblog
author_rank: Unknown
timestamp: October 10, 2024, 12:14:42 am
content: Quote from: Furna on October 09, 2024, 09:39:37 pmOne supplier was supposed to have stock end of this month I think.

author: xKertx
author_rank: Regular Contributor
timestamp: October 10, 2024, 03:27:12 am
content: tme.eu has 4pcs in stock.

author: mihaip
author_rank: Newbie
timestamp: October 11, 2024, 11:54:33 am
content: From your experience do you guys think that first batch of a Brymen multimeter can have issues and I would better wait a while (how long) to get the BM2257?Also Dave, what chip do you think is that BTCS26A. I could not find any 102 pin chip that matches.RegardsMihai

author: J-R
author_rank: Super Contributor
timestamp: October 11, 2024, 08:15:24 pm
content: Quote from: mihaip on October 11, 2024, 11:54:33 amThe BM78x had a few minor issues at release that were slowly fixed over time. Personally, I bought one of the early BM789 units and it has a few known issues. The only issue I was able to fix myself was to install the shield over the speaker. The other issues are in firmware and it would cost too much to try to get it updated by a dealer.While the BM2257 appears to be an evolution of the BM257, it may have some new issues that will take time for buyers to discover. So if that is a concern for you, then it is probably better to wait as long as possible before buying it.

author: EEVblog
author_rank: Unknown
timestamp: October 11, 2024, 11:26:16 pm
content: Quote from: mihaip on October 11, 2024, 11:54:33 amI still use an original batch BM235 meter that's has like a half dozen firmware updates since then and it's fine. The updates are usually obscure stuff that most people will never encounter.Sorry, can't tell you what the chip is, I'm under NDA.

author: EEVblog
author_rank: Unknown
timestamp: October 11, 2024, 11:28:02 pm
content: FYI, I've ordered the BM2257 under my branding. Not sure if I'll continue to offer the BM235 long term as a result, but I still have a lot of stock left.

author: J-R
author_rank: Super Contributor
timestamp: October 12, 2024, 05:03:09 am
content: People will probably always be looking for both the BM235 and the BM2257, depending on what they do frequently. There are quite a few differences.

author: EEVblog
author_rank: Unknown
timestamp: October 12, 2024, 05:33:19 am
content: Quote from: J-R on October 12, 2024, 05:03:09 amExactly the same size and shape, the BM2257 just has some extra features. So apart from a relatively small cost difference, the BM2257 looks better in every regard.

author: xKertx
author_rank: Regular Contributor
timestamp: October 12, 2024, 06:57:29 am
content: Quote from: EEVblog on September 12, 2024, 05:13:58 amWhat about the viewing angle of the screen?The 235 had contrast issues when viewed at angles. Have they improved that?And are the digits the same size on both models? To my eyes the digits on 2257 looks slightly smaller on the photo.

author: mihaip
author_rank: Newbie
timestamp: October 12, 2024, 09:36:36 am
content: Can I update the Firmware myself on BM2257? Does Brymen publish fw updates?I'm quite skilled with computers so it wouldn't be a problem for me.

author: rsjsouza
author_rank: Super Contributor
timestamp: October 12, 2024, 12:34:19 pm
content: Quote from: EEVblog on October 12, 2024, 05:33:19 amBeing top of its range of general purpose compact meters, that is a meter that has very little compromises and it is the one to have IMO.

author: Furna
author_rank: Frequent Contributor
timestamp: October 12, 2024, 12:36:35 pm
content: Quote from: rsjsouza on October 12, 2024, 12:34:19 pmin blue

author: EEVblog
author_rank: Unknown
timestamp: October 13, 2024, 07:19:57 am
content: Quote from: xKertx on October 12, 2024, 06:57:29 amSame 20mm digits.Slightly less viewing angle above than one BM235 I tried, not very noticable.

author: EEVblog
author_rank: Unknown
timestamp: October 13, 2024, 07:20:33 am
content: Quote from: mihaip on October 12, 2024, 09:36:36 amNo, you can't. Only dealers can update the firmware.

author: mihaip
author_rank: Newbie
timestamp: October 14, 2024, 09:16:06 am
content: Quote from: EEVblog on October 11, 2024, 11:26:16 pmBummer that I can't update fw myself.So how did you update the firmware of your BM235 if only the dealer can do it?How are normal people like me update the firmware if there is something serious? Are they sending the meter back to the dealer?Thanks all again for all your feedback !

author: mihaip
author_rank: Newbie
timestamp: October 14, 2024, 10:04:55 am
content: One more question: it seems it does not work well with Eneloops. BM2257 Low battery triggers at 2.5V, while BM257 at 2.3V. BM235 also 2.5V, so BM2257 would behave about the same as BM235 with Eneloops.Any comments about this?

author: EEVblog
author_rank: Unknown
timestamp: October 14, 2024, 10:14:10 am
content: Quote from: mihaip on October 14, 2024, 09:16:06 amThe BM235 is an older design with an OTP ROM, it can't be upgraded.QuoteBasically, you don't. No differen to countless other multimeters that have fixed firmware.

author: Furna
author_rank: Frequent Contributor
timestamp: October 14, 2024, 10:34:12 am
content: Quote from: EEVblog on October 14, 2024, 10:14:10 amI can see more and more (young) people thinking fixed firmware is not accpetable.@mihaip there are scenarios where a fixed firmware is the right choice. for a multimeter is a matter of where/what situation you use it

author: rsjsouza
author_rank: Super Contributor
timestamp: October 14, 2024, 12:28:22 pm
content: Quote from: Furna on October 14, 2024, 10:34:12 amIndeed. Especially if the hardware goes through revisions, which can be hard to track especially years after the initial releases.

author: EEVblog
author_rank: Unknown
timestamp: October 14, 2024, 10:25:57 pm
content: Quote from: Furna on October 14, 2024, 10:34:12 amPresumably that's why Brymen don't want to make it publicly available or even reference it's possible.What percentage of multimeters on the market have publicly upgradable firmware? It's probably only a handful of meters.

author: EEVblog
author_rank: Unknown
timestamp: October 14, 2024, 11:52:35 pm
content: Just got an email from Brymen saying the BM2257 uses an OTP ROM like the BM235.So the programming port must just be for assembled PCB programming. Makes sense because the BM78x uses a header accessable through the battery compartment, but the BM2257 is internal.

author: AVGresponding
author_rank: Super Contributor
timestamp: October 15, 2024, 07:51:36 am
content: Quote from: EEVblog on October 14, 2024, 10:25:57 pmI can't imagineanydo, that have (genuine) CAT ratings. Happy to be proved wrong though

author: EEVblog
author_rank: Unknown
timestamp: October 15, 2024, 08:34:03 am
content: Quote from: AVGresponding on October 15, 2024, 07:51:36 amMy 121GW does, UL listing.Fluke 289I forgot the BM869s doesKeysight U1272AUni-T 181ABasically only the high end high feature packed ones that have USB or SD card interfaces that make it easy.I don't know of any low or mid range meters that do and rely on a factory micro programmer header.

author: 2N3055
author_rank: Super Contributor
timestamp: October 15, 2024, 09:44:14 am
content: Quote from: EEVblog on October 15, 2024, 08:34:03 amMETRIX MTX3293 and whole that family of meters also have updatable FW and full listing.Manufacturer guarantees changes in FW did not impact performance in a way that testing is invalidated.In case it does, they need to retest and then new measurements apply to meters with new FW.

author: rsjsouza
author_rank: Super Contributor
timestamp: October 15, 2024, 09:48:54 am
content: Quote from: 2N3055 on October 15, 2024, 09:44:14 amThe Keysight U1282A also has upgradable firmware. But updates were very minimal throughout the initial years and now they are non-existent. It is a mature product.

author: Furna
author_rank: Frequent Contributor
timestamp: October 16, 2024, 07:18:09 pm
content: Quote from: EEVblog on October 15, 2024, 08:34:03 amI am not aware you can upgrade the firmware on BM869s; I own one and did some research on it before buying.The only person I know about that was able to "upgrade" the firmware on BM869s was Joe Smith replacing the chip thus loosing the calibration.

author: Kean
author_rank: Unknown
timestamp: October 16, 2024, 07:48:05 pm
content: Quote from: Furna on October 16, 2024, 07:18:09 pmYes, and that required pre-programmed chips sent by Brymen (probably OTP parts).That is not something they would normally do, but as I understood it Joe was helping them diagnose some issues he encountered.

author: EEVblog
author_rank: Unknown
timestamp: October 16, 2024, 11:00:12 pm
content: Quote from: Furna on October 16, 2024, 07:18:09 pmAh, yes, I stand corrected.

author: mihaip
author_rank: Newbie
timestamp: October 17, 2024, 11:59:23 am
content: Since the fw of BM2257 is not updatable, I will wait until Dave will start selling it, so I'm confident that he tested it thoroughly and everything works fine and any early production bugs have been fixed.

author: kwass
author_rank: Frequent Contributor
timestamp: October 19, 2024, 01:56:35 pm
content: I just received a BM2257 from TME and it's quite nice.It love everything about this meter (you know the specs and at meets them all so not comments on that) it's very fast to auto range and test continuity (the best continuity tester I've can remember on any multimeter), great visibility, remembers some settings between power cycles, is small and feels just right in my hand, etc.. I have only two minor gripes: (1) - the diode test/beep is easily fooled by resistors in the range of 1K ohms, so make sure you're actually testing a diode and that it's out of circuit. (2) - The autohold works great but when you diastole the button/warning beeps (hold RANGE when powering on) it disables the autohold beep. It does not disable the continuity beep nor diode test beep, this seems inconsistent to me.

author: SeoulBigChris
author_rank: Regular Contributor
timestamp: October 21, 2024, 10:16:46 pm
content: How does this compare, physical enclosure size wise, to the 121GW and the BM-786? I can’t quite put my finger on it, but the 121GW always feels a little unbalanced to me. Even though I like the features of the 121GW best, I find myself reaching for the BM-786 more often than not, just because of the shape.I have often wondered if the 121GW would benefit from a redesigned bail / stand. When I do use the 121GW, I usually figure out how to prop it up or lay it flat without extending the stand.

author: EEVblog
author_rank: Unknown
timestamp: October 22, 2024, 12:14:33 am
content: Quote from: SeoulBigChris on October 21, 2024, 10:16:46 pmSame as the BM235

author: SeoulBigChris
author_rank: Regular Contributor
timestamp: October 22, 2024, 03:13:59 am
content: I read from the spec sheets, the 121GW is 60 mm thick and these others are 50 or 51 mm thick.

author: EEVblog
author_rank: Unknown
timestamp: October 22, 2024, 03:32:03 am
content: Quote from: kwass on October 19, 2024, 01:56:35 pmCofirmed and reported to Brymen.Also, when you release the probes after hearing the AutoHold beep in Ohms mode, the display resets and autoranges before displaying the captured reading. This is rather confusing. It doesn't do this in voltage mode. Also reported.

author: EEVblog
author_rank: Unknown
timestamp: October 22, 2024, 03:32:41 am
content: Quote from: SeoulBigChris on October 22, 2024, 03:13:59 amYes, the 121GW had to be thicker because it uses AA batteries.

author: EEVblog
author_rank: Unknown
timestamp: October 28, 2024, 09:18:16 am
content: Quote from: EEVblog on October 22, 2024, 03:32:03 amBrymen's response:Quote

author: rsjsouza
author_rank: Super Contributor
timestamp: October 28, 2024, 03:29:27 pm
content: You got to give many props for Brymen's interest in answering questions from the customer base.

author: LinusSch
author_rank: Newbie
timestamp: October 30, 2024, 11:54:11 am
content: Finally, some discussion on the 2257! I first saw this in May or so, on one of the Brymen websites. It eventually appeared on TME for preorder and for sale but until now I've seen no discussion, no comments from users or reviewers. I was starting to think I might have to bite the bullet and do that part myself. Alas, I'm out of funds for such things at the moment.Riddle me this: why are all compact multimeters more or less low-end? The 121GW seems to be the only exception. The Fluke 110 series is very limited in functionality, perhaps most notably missing AutoHold which I think is a killer feature in many of the same situations where a compact meter is the one to have. The Keysight 1230 series do have AutoHold (with 10 measurements of memory, nice) but are still limited to three input jacks and the general sentiment seem to be that they are disappointing quality-wise. So... the Brymen 2250 series seems to me as if it has very limited competition.Quote from: EEVblog on October 28, 2024, 09:18:16 amIt is great that we get answers, this is a large reason that I hold Brymen as my preferred meter-making company!To keep on updating the display until surely no reading, only then showing the hold value - that makes sense to me and is another of the reasons I felt good about buying my BM789. A rare occasion for sure, but if the meter is reading something when I don't expect it to I'm grateful that it would show me.But to disable the AutoHold beep when disabling button beeps, this does not make sense to me.The real value of the Hold feature is (to me) when you do not have eyes on the display while making the measurement. But it requires you to have a hand on the meter instead which may be equally impossible. AutoHold then makes it possible, on top of making easy what Hold makes cumbersome. Without AutoHold the solution is to have a second person reading the multimeter while the first person executes the difficult-to-reach probing. This probably never happens on a bench, but it is frustratingly common when working on a vehicle or similar.If I was able to see an indicator on the display I could just as easily read the value without using Hold at all. Right? Unless my short-term memory is having an unusually bad day I don't think I see the point of Hold without a beep, Auto or not.IME, YMMV, but definitely not a humble opinion in this case.

author: EEVblog
author_rank: Unknown
timestamp: October 30, 2024, 09:56:37 pm
content: Quote from: LinusSch on October 30, 2024, 11:54:11 amAgreed, it's the entire point of AutoHold, you aren't looking at the display.

author: 0Anonym
author_rank: Newbie
timestamp: November 11, 2024, 10:33:56 pm
content: Hey,Are there any updates on a possible release date or the development status?Looking forward to it!

author: EEVblog
author_rank: Unknown
timestamp: November 11, 2024, 11:15:46 pm
content: Quote from: 0Anonym on November 11, 2024, 10:33:56 pmMy unit are due late December.Brymen do not make and stock, they build to order.

author: Furna
author_rank: Frequent Contributor
timestamp: November 12, 2024, 06:09:11 pm
content: Quote from: EEVblog on November 11, 2024, 11:15:46 pmI guess we will have an announcemnt here on this forum topic (?)

author: Furna
author_rank: Frequent Contributor
timestamp: December 26, 2024, 06:30:06 pm
content: Quote from: EEVblog on November 11, 2024, 11:15:46 pmIt is now late December ... any update?Thank you.

author: BILLPOD
author_rank: Frequent Contributor
timestamp: December 26, 2024, 08:35:43 pm
content: I have often wondered if the 121GW would benefit from a redesigned bail / stand. When I do use the 121GW, I usually figure out how to prop it up or lay it flat without extending the stand.I took the rubbery boot off my 121GW and purchased a 3D printed stand that worksBEAUTIFULLY. (I don't want to get in the 3D printing rabbit hole).

author: EEVblog
author_rank: Unknown
timestamp: December 26, 2024, 09:17:44 pm
content: Quote from: Furna on December 26, 2024, 06:30:06 pmThere was a delay, now due mid Jan

author: 0Anonym
author_rank: Newbie
timestamp: January 17, 2025, 10:03:12 pm
content: Hey, its mid-January so just wanted to ask if there are any updates.Also, to get one for sure I wanted to ask if its going to be available on Simons Electronics at launch or where Europeans should order instead.Will the EEV Blog version come with the PC Adapter?Thanks in advance.

author: EEVblog
author_rank: Unknown
timestamp: January 17, 2025, 11:33:17 pm
content: Quote from: 0Anonym on January 17, 2025, 10:03:12 pmStock turned up yesterday. Todays job is to get it on the store. PC serial adapter is separate.It's up to Simon is he's going to sell it locally.

author: Furna
author_rank: Frequent Contributor
timestamp: January 17, 2025, 11:36:00 pm
content: Quote from: EEVblog on January 17, 2025, 11:33:17 pmDo you work on Saturdays? Half past midnight now in Germany, will check the store in 8 hours

author: EEVblog
author_rank: Unknown
timestamp: January 18, 2025, 01:08:09 am
content: Quote from: Furna on January 17, 2025, 11:36:00 pmNot often, but I'm here today as rain has cancelled some kids stuff.It's now on the store, but I have yet to do the manual and some other stuff ince the serial interface.https://eevblog.store/products/eevblog-bm2257-multimeter

author: Furna
author_rank: Frequent Contributor
timestamp: January 18, 2025, 01:16:15 am
content: Quote from: EEVblog on January 18, 2025, 01:08:09 amSorry for your kids missing their open air time.Having issue finalizing the order "No delivery available"

author: EEVblog
author_rank: Unknown
timestamp: January 18, 2025, 01:26:31 am
content: Quote from: Furna on January 18, 2025, 01:16:15 amOdd. Can't see any issue on the listing compared to other products.DM me your address so I can test it.

author: EEVblog
author_rank: Unknown
timestamp: January 18, 2025, 01:37:02 am
content: Quote from: EEVblog on January 18, 2025, 01:26:31 amI put a random addres in Germany and got the same message. Can you try another product, I want to see if it's the new product or not.EDIT: I think it's the new product somewhow...EDIT2: I think I fixed it, please try again!

author: Furna
author_rank: Frequent Contributor
timestamp: January 18, 2025, 01:41:12 am
content: Quote from: EEVblog on January 18, 2025, 01:37:02 amI was able to finalize order #2252 *without* BM2257

author: EEVblog
author_rank: Unknown
timestamp: January 18, 2025, 01:46:55 am
content: I think I fixed it, please try again.Stupid Shopify doesn't automatically add new products to the "physical store"

author: EEVblog
author_rank: Unknown
timestamp: January 18, 2025, 01:49:45 am
content: Quote from: Furna on January 18, 2025, 01:41:12 amWoah, you finalised the order without the meter?If you did want the meter I'll have tro refund and cancel that order, is that what you want?

author: Furna
author_rank: Frequent Contributor
timestamp: January 18, 2025, 01:52:04 am
content: Quote from: EEVblog on January 18, 2025, 01:46:55 amOrder #2253 finalized with BM2257 included!

author: Furna
author_rank: Frequent Contributor
timestamp: January 18, 2025, 01:54:22 am
content: Quote from: EEVblog on January 18, 2025, 01:49:45 amI want #2252 + #2253minus the double shipping expenses

author: EEVblog
author_rank: Unknown
timestamp: January 18, 2025, 01:55:48 am
content: Quote from: Furna on January 18, 2025, 01:52:04 amThanks. But the problem is now that you have paid for two separate shipping charges, and I can't manually add things. Let me cancel the 2251 order for the case and probes and I'll just include a case in the BM2257 order. The probes are already included, unless you need a spare set?

author: EEVblog
author_rank: Unknown
timestamp: January 18, 2025, 01:57:36 am
content: Quote from: Furna on January 18, 2025, 01:54:22 amI'll refund the shipping on the 2252 order and will ship as one lot. It gets messy.

author: Furna
author_rank: Frequent Contributor
timestamp: January 18, 2025, 02:03:44 am
content: Quote from: EEVblog on January 18, 2025, 01:57:36 amGot the refund already; thank you.Sorry for the mess ... happy we figured it out.Hope the rain at your place stops soon!

author: mbarszcz
author_rank: Contributor
timestamp: January 23, 2025, 03:18:43 am
content: Dave,Do you know if the LoZ circuit is the same on the BM2257 as it was on the BM235? After this interesting discussion:https://www.eevblog.com/forum/testgear/bm235-loz-mode/msg5734755/#msg5734755I'm curious if the behavior has changed?

author: rdenney
author_rank: Regular Contributor
timestamp: January 23, 2025, 05:44:07 pm
content: @EEVBlog Dave, you mentioned (somewhere--now I can't find where) this was available on Amazon for a slightly higher price, and you provided a link from your YouTube video. But that link brings up the previous model BM235. Will the new model be supplied? I'm not sure I need yet another handheld DMM, but, of course, that's crazy talk.Rick "always needs another DMM" Denney

author: Furna
author_rank: Frequent Contributor
timestamp: January 23, 2025, 06:39:34 pm
content: Quote from: rdenney on January 23, 2025, 05:44:07 pmThe link to Amazon is on the EEVBlog shop page dedicated to the new BM2257https://eevblog.store/products/eevblog-bm2257-multimeter"Americans can now purchase the BM2235 though Amazon!"and I confirm it brings up the "old" BM235

author: floobydust
author_rank: Super Contributor
timestamp: January 23, 2025, 09:24:40 pm
content: Some confusion about the smaller mA/uA range fuse.BM2257, BM2251 User's Manual(r3)specifies 0.63A fuse (ASTM HV620.0.63)ASTMwebsite only offer 0.6A fuse (HV620.0.6) and meter face is labelled 0.6A I guess for the range.Dave can you comment if this is a custom part? Your store has the 0.4A part for the EEVblog BM235, BM786, and 121GW Multimeters.

author: EEVblog
author_rank: Unknown
timestamp: January 23, 2025, 10:19:52 pm
content: Quote from: floobydust on January 23, 2025, 09:24:40 pmIt is supplied with a 630mA HV620 1000V fuse from ASTM. No part number on it because that's usually on the bulk box only.So unless the normal 600mA is actually marked 630mA, yeah, it might be custom.I can't see why given the BM235 and BM786 also have a 600mA range and use the 400mA fuse.It's going to be annoying if I have to stock both.I'll ask them.

author: EEVblog
author_rank: Unknown
timestamp: January 23, 2025, 10:22:10 pm
content: Quote from: rdenney on January 23, 2025, 05:44:07 pmNo, if you want the BM2257 you'll have the wait for the BM2257 listing which I haven't done yet. The old BM235 link is there because I copied the listing over.

author: EEVblog
author_rank: Unknown
timestamp: January 23, 2025, 10:23:41 pm
content: Quote from: mbarszcz on January 23, 2025, 03:18:43 amAs mentioned here, it's different:https://www.eevblog.com/forum/testgear/bm235-loz-mode/msg5723763/#msg5723763I can measure a 1.5V battery at full 1mV resolution on the BM2257. Doesn't work at all on the BM235I forgot that's an important difference to the BM235, so have added that to the listing.

author: Kessler
author_rank: Newbie
timestamp: January 24, 2025, 01:01:12 am
content: I just got my meter today! I am a beginner and this is the first nice DMM I have had. Everything in the past has been cheap DMMs. Now off to go figure out what relay on my car is failing.

author: EEVblog
author_rank: Unknown
timestamp: January 24, 2025, 04:15:43 am
content: Quote from: EEVblog on January 23, 2025, 10:19:52 pmBrymen replied and said the fuse is now 630mA because too many people questioned why a 400mA fuse (originally SIBA) was used in a 600mA range meter on the BM230 and BM780 series.So with this new design BM2257 they submitted the meter with the ASTM 630mA fuse to UL and it was approved under IEC/EN/UL 61010-1/-2-033, so 630mA it is.Why 630mA instead of 600mA? They didn't say, but the BM2257 does actually measure above 600mA in practice, so maybe they decided it would be nice to have a little over 600mA?They can't retroactively change the BM230 and BM780 series to 630mA ASTM because technically it would require re-submitting the meter for UL approval again. And Brymen are super fussy about doing UL approval by the book.Without a doubt the 600/630mA ASTM could also be used in the other models, but they can't officially say that.

author: floobydust
author_rank: Super Contributor
timestamp: January 24, 2025, 07:07:25 pm
content: Limiting factor is the shunt resistor clamp-diodes, they must clear the fuse and never go open circuit.Did you notice BM2257 they went overboard - five of 15A (350A 1/2 cycle surge) SMC parts - biggest diodes ever used thereNot sure why Brymen upsized when everyone else has been using 1A (4007, M7) parts (Fluke, Agilent, BM235, 786, 857 and others) for many years.It's great they are huge and safer, not likely to not care at all about clearing bigger fuses.New regulatory testing costs a lot of money. To save lab time I will submit a few variants for testing at the same time.Whatever meets spec and survives the tests gets put into the report, so you don't get locked in to using one specialty part.BM235 pics showed 500mA Siba GZ DMI Prot, 70-172-40/0.5A so that series would likely work too, they have a 630mA part.

author: Monkeh
author_rank: Super Contributor
timestamp: January 24, 2025, 07:16:27 pm
content: Quote from: floobydust on January 23, 2025, 09:24:40 pmI'd bet money it's exactly the same fuse, they just put a different label on it because someone preferred less rounding (see:Renard series). I can't see the fuse wire being made to tolerances tight enough to actually differentiate at that level, 30mA is in the noise.E: Then again, they do offer the 315mA and 400mA options, only 30mohm between them..I wouldn't bat an eyelid at the difference if I needed a replacement, anyway.

author: Gyro
author_rank: Super Contributor
timestamp: January 24, 2025, 07:20:22 pm
content: Quote from: EEVblog on January 24, 2025, 04:15:43 amBecause 630mA is an industry standard value (like 3.15A for instance). Look on a main distributor site and you will find a couple of 600mA fuses but dozens of 630mA.Edit: Snap.

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 24, 2025, 08:07:08 pm
content: SIBA 7017240 comes in a 630mA SKU that should be an equivalent to the ASTM part:- SIBA 7017240.0,63 630mA 1000V IR 30kA (6 x 32mm)The SIBA fuses aren't too hard to find at a reasonable price.-https://www.aliexpress.us/item/3256806238128876.html(if you trust Aliexpress seller) $12 for 10, shipping included-https://www.aliexpress.us/item/3256802828651015.html(if you trust Aliexpress seller) $20 for 20, shipping includedA more trustworthy vendor (but I don't know what the shipping would be):-https://www.tme.eu/en/details/zgssh-0.63a/fuses-6-3x32mm-super-fast/siba/7012540-0-63/$3 eachThe 500mA variant is even easier to find and might make an acceptable replacement.

author: Furna
author_rank: Frequent Contributor
timestamp: January 24, 2025, 08:19:02 pm
content: Quote from: mwb1100 on January 24, 2025, 08:07:08 pmFor the 11A I am thinking this one DMM-B-11Ahttps://www.welectron.com/mediafiles/datasheets/cooper-bussmann/Cooper-Bussmann_DMM-B_Datasheet.pdf

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 24, 2025, 09:07:07 pm
content: Yes, the 11A fuse in Brymen meters is the same as the Fluke 11A fuse - any Bussman DMM-11, DMM-B-11 or DMM-B-11-r will work. Also the Littlefuse FLU011 or FLU 11A (I think any 11A Littlefuse with an ID that begins "FLU" will be interchangeable). These fuses are generally easy to find, but seller's asking price varies widely. You should be able to find one for around $10 or less without trouble, which looks like Welectron's price.

author: Furna
author_rank: Frequent Contributor
timestamp: January 24, 2025, 09:16:32 pm
content: As soon as my BM2257 arrives, I will take it apart to honour the EEVBlog motto ... and if it really contains an Bussmann KLM-12 I will remove and sell it on EBayIt is 76€ on DigiKey.That is ridiculos

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 24, 2025, 09:43:57 pm
content: Quote from: Furna on January 24, 2025, 09:16:32 pmMouser is similar pricing... everyone else is a more sane $10 each give or take (and I'm not convinced that they are fakes). I'd bet that the Digikey/Mouser pricing is a mistake where they are quoting the boxed units of 10 as "Quantity 1". Of course anyone ordering should confirm that with them and have the pricing fixed before ordering.By the way, what makes you think the BM2257 might come with a KLM-12? Dave's photos showed the ASTM HV110.

author: Furna
author_rank: Frequent Contributor
timestamp: January 24, 2025, 09:58:05 pm
content: Quote from: mwb1100 on January 24, 2025, 09:43:57 pmI checked only DigiKey and Mouser ...Pag 16 of the manual mentions Bussmann or ASTM (in this order).I guess ASTM is cheaper than Bussmann so Braimen will use Bussmann only in case of shortages.

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 24, 2025, 10:13:07 pm
content: Quote from: Furna on January 24, 2025, 09:58:05 pmInteresting... I didn't notice that when browsing the manual. Seems a little strange to specify the unusual Bussman KLM-12 (which is 12A/600V) instead of the DMM-11 which pretty much every handheld multimeter in this class uses. The Bussman DMM-11 has the same specs as the ASTM H110.11A except that the IR rating of ASTM's is 30kA versus the DMM-11's 20kA (the KLM-12 has IR 50kA).

author: EEVblog
author_rank: Unknown
timestamp: January 24, 2025, 10:36:11 pm
content: Quote from: Furna on January 24, 2025, 09:58:05 pmMy BM2257 stock has ASTM for both.I'm the one that found and introduced Brymen to ASTM, they used to use SIBA. It seems that they may have now standardised on them, and yes, that would be because of cost. The ASTM's are very cost effective when you buy in bulk. I buy thousands at a time.

author: EEVblog
author_rank: Unknown
timestamp: January 24, 2025, 10:42:12 pm
content: Quote from: floobydust on January 24, 2025, 07:07:25 pmI suspect it's because they knew they were going for a bigger fuse rating for UL testing so they went full belt'n'braces to make sure. They are monsters.

author: EEVblog
author_rank: Unknown
timestamp: January 24, 2025, 10:55:03 pm
content: Now it's got me wondering if I have to now stock two different fuses (400mA + 630mA) or standardise on either 400mA or 630mA for all meters (BM2257, BM235, BM786, 121GW)Obviously the 400mA will work in all, but the 630mA is technically not UL rated for the other meters apart from the BM2257, but of course in practice it will work just fine and be safe for all the 600mA range meters.

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 24, 2025, 11:11:08 pm
content: Quote from: EEVblog on January 24, 2025, 10:36:11 pmWow!Quote from: EEVblog on January 24, 2025, 10:55:03 pmMaybe change the package to:2 x HV110 11A 30kA 1000V HRC (10x38mm)2 x HV620 400mA 10kA* 1000V HRC (6x32mm)3 x HV620 630mA 10kA* 1000V HRC (6x32mm)*the ASTM data sheetsays H620 fuses are "Self-certified for Breaking Capacity 30kA @ 1000VAC/DC for 800mA and below"The datasheet also doesn't mention a 630mA H620 fuse, but since Brymen is installing them I'm guessing it is available to the likes of someone who buys thousands.I'd guess a package like that would make as many people happy as unhappy, making it a wash happinesswise. People who want to go by-by-the book would be able to and would have a couple "not by-the-book" spares to get them by in a pinch if need be (or forever if they eased up). No idea how much more trouble it'd be for you.

author: EEVblog
author_rank: Unknown
timestamp: January 24, 2025, 11:45:34 pm
content: Quote from: mwb1100 on January 24, 2025, 11:11:08 pmIt's trouble either way, guaranteed!I think the mixed bag is probably a good idea.

author: Kleinstein
author_rank: Super Contributor
timestamp: January 25, 2025, 10:34:03 am
content: The 11 A fuse rarely blows. On the other side the 400/600 mA fuses may blow from time to time. They are really fast and I manged to blow one from inrush current to some electrolytic capacitors.I would not mind the 600/630 mA difference very much, but the 400 mA fuse is still sufficiently different. It's the users to decide if they want a slightly more robust fuse or the original rating. Chances are it would be better to offer both sizes. There may also be owners of other meters that are looking for a spare fuse. I don't think a mixed bag would make much sense - one either wants the safe / certified way or the slightly more robust version. For those meters that specify 600 mA, very few would settle for a 400 mA fuse.

author: EEVblog
author_rank: Unknown
timestamp: January 25, 2025, 12:07:34 pm
content: Quote from: Kleinstein on January 25, 2025, 10:34:03 amThat's why my mixed bag has 2 x 11A and 5 x 400mAQuoteEither way I've just ordered 1000 of both.I might just offer two different mixed bags. Although I can see the emails now "you sent me the 400mA and I wanted the 600mA"

author: mihaip
author_rank: Newbie
timestamp: January 29, 2025, 06:45:45 pm
content: Dave, when will you get new stock of BM2257 ?

author: Fungus
author_rank: Super Contributor
timestamp: January 29, 2025, 09:09:17 pm
content: Pop quiz: How many mA does it take to blow a 400mA fuse?

author: geralds
author_rank: Contributor
timestamp: January 29, 2025, 10:10:45 pm
content: Hi, I am new to electronics, and new to this forum - thus apologies if I am missing any convention (or if I am posting in the wrong thread).I need a DMM for electronics repairs, primarily home electronics (laptops, hifi equipment, possibly some dehumidifiers, etc.). I have been looking at the BM2257, mainly because of the reviews and comments by Dave and others on this blog. Alternatives in my selection are AN870, ZT219, and H118E (though not my preference as they seem to be less solid and less accurate?). Or the Fluke 115 as a set with TLK-225-1 as this seems to be on promotion at the moment (but I understand functionality may be less than the BM2257?).Against this backdrop / intended use, would the BM2257 be fit for purpose? Would you recommend another DMM? BM2257 is more or less top end of my intended budget. Fluke 115 cost more, but it already has the test lead set included (which I would need to add to the price of the BM2257 for a fair comparision). I would rather spend this money on the BM or the Fluke if the higher quality justifies when compared with the cheapos.Many thanks for your help and input,Gerald

author: EEVblog
author_rank: Unknown
timestamp: January 29, 2025, 10:32:11 pm
content: Quote from: geralds on January 29, 2025, 10:10:45 pmWelcome to the forum.I might be biased, but the BM2257 is probably the most feature packed you will get the for the price in a top brand. Plenty for electronics and home repair. The Fluke 115 is an excellent meter, but doesn't have the handy EF function or TouchHold.Both are plenty for home electronics and repair use.THat being said, there might technically be better bang-per-buck to be had in the lower priced tools like the AN870, which would also suit your purpose.https://www.eevblog.com/forum/testgear/looking-at-three-very-different-multimeters-(aneng-an870-and-eevblogs-meters)/You can get cheap probe adapters of various sorts from Aliexpress if you need those. e.g.https://youtu.be/tz4cYPj3Kls?si=LWfqDO8283CIK-V7&t=864

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 29, 2025, 10:40:30 pm
content: Quote from: geralds on January 29, 2025, 10:10:45 pmThe BM2257 is very newly released. As far as I know it hasn't been reviewed by anyone, more or less just comparisons of the specs and build when compared to the BM235 (and to a lesser extent the BM257s). It's expected that the BM2257 will perform and have a robustness similar to the BM235/BM257s. I believe it has all of the features of the BM235 and the BM257s plus more. The specs are very similar, but there are some differences - minor ones in my opinion.Probably the biggest features over the BM235 are PC connectivity, which requires an additional purchase of a interface cable, (the BM257s also had PC connectivity) and autohold.The BM2257 look like it will cost about $25 - $40 more than BM235. I think the consensus is that the BM235 is considered a pretty good value considering design and build quality and feature set. I'd expect the BM2257 to be similarly regarded, but that's just my expectation, but it is at a higher price point.The Fluke 115 looks to have a similar feature set to the BM235 (i haven't done a point-by-point analysis of the datasheets though), but costs more than twice as much.The other meters you mention are significantly less expensive, and are probably a better way to go when starting out. After using them for a while you'll have a much better idea of what you might be willing to pay more for. They should be pretty darn accurate, where they might be lacking is in robustness and safety. For electronic work those aren't too much an issue, for mains work opinions differ.

author: EEVblog
author_rank: Unknown
timestamp: January 29, 2025, 10:42:27 pm
content: Quote from: Fungus on January 29, 2025, 09:09:17 pmIn theory, 401mA after quite some time.At 400mA the fuse should not break after an infinite time.In practice, any random value if you bought a fake off ebay, or if genuine follow the parametric charts and add your own window, add salt to flavour.

author: EEVblog
author_rank: Unknown
timestamp: January 29, 2025, 10:45:05 pm
content: Quote from: mihaip on January 29, 2025, 06:45:45 pmStock keeping error, I have them, check again.

author: Furna
author_rank: Frequent Contributor
timestamp: January 29, 2025, 10:47:04 pm
content: Quote from: mihaip on January 29, 2025, 06:45:45 pmGemini:A 400mA fuse is designed to blow when the current flowing through it exceeds 400 milliamperes (mA).**Therefore, it takes slightly more than 400mA to blow a 400mA fuse.*** **Note:** The exact current required to blow the fuse can vary slightly depending on factors like the fuse's specific design, age, and operating temperature.

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 29, 2025, 10:56:10 pm
content: Quote from: Fungus on January 29, 2025, 09:09:17 pmDepends on the fuse.According to thisdatasheet for the SIBA 7017240, a fuse which has been used in Brymen meters and other fast blow ceramic fuses used in meters might be similar to:- at 400mA the fuse will last at least 1 hour, but could (and should) last much longer- at 1.6A the fuse will blow within 60 ms- at 4A the fuse will blow within 6 ms(assuming I'm reading the table and chart correctly)

author: bdunham7
author_rank: Super Contributor
timestamp: January 29, 2025, 11:01:06 pm
content: Quote from: geralds on January 29, 2025, 10:10:45 pmIf your budget allows it, avoid the low-end stuff. Either the Fluke or Brymen will be good.What is the promotion Fluke is offering? Fluke stuff is expensive, especially in Europe so waiting for a sale is wise. I'd actually recommend you look at the 116 plus maybe a current clamp. A while back I got such a set on promotion with a pretty good set of leads, case, etc. It might seem strange not having a current range, but since the 115 only has a 10A range anyway I don't think you're losing much. You don't want to be running mains current through the meter like that. Since you say you're a novice, the 116 has the advantage that it is literally impossible to blow it up by connecting it wrong to any voltage you'll find in your household--except the microwave oven and please don't ever open that up if you don't know exactly what you are doing (and best not even then). The 116 and BM2257 also have a Low-Z mode that you may not understand at the moment but is IMO a very valuable feature.If you want good test leads, look at ProbeMaster. Also, I believe if you buy the Brymen BM2257 from the EEVBlog store you get some pretty good test leads in the package. The TLK-225 set is nice stuff, but geared more towards industrial electricians. I have some of those probes and clamps and don't use them all that often. It seems a bit odd to offer them with the 115 because they're more something you'd use with a 179, 87-V or 287 since those are CATIII/1000V meters.

author: tautech
author_rank: Super Contributor
timestamp: January 29, 2025, 11:01:16 pm
content: Quote from: EEVblog on January 29, 2025, 10:42:27 pmGood topic for a video.Quality vs no name vs Normal vs Slow blow vs Fast blow.

author: EEVblog
author_rank: Unknown
timestamp: January 29, 2025, 11:34:35 pm
content: Quote from: tautech on January 29, 2025, 11:01:16 pmIt would be, except it's basically a statistical thing, so you have to run a lot of them.

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 29, 2025, 11:41:14 pm
content: Quote from: EEVblog on January 29, 2025, 11:34:35 pmBut what's more popular than a YT where things blow up?(though fuses popping might not be so exciting)

author: EEVblog
author_rank: Unknown
timestamp: January 29, 2025, 11:44:43 pm
content: Quote from: mwb1100 on January 29, 2025, 11:41:14 pmSadly you don't get to see anything with sand filled HRC fuses

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 29, 2025, 11:56:17 pm
content: Quote from: EEVblog on January 29, 2025, 11:44:43 pmof course...

author: geralds
author_rank: Contributor
timestamp: January 30, 2025, 12:01:45 am
content: @eevblog, @mwb1100, @bdunham7 (not sure whether "@" + user works like in Outlook?)Many thanks for your super fast replies, which are very helpful indeed! What a forum!I will then look again at the AN870, despite my tendancy for the BM2257 as it seems more robust and thus should hopefully last substantially longer. Plus a set of ProbeMaster and Hirschmann leads/probes.Re Fluke 115/225 set, there seems to be a promotion in Europe for around EUR 250. But noted about (lack of) Auto-Hold function, LoZ and usefulness about probes/test leads for electronics, so it seems the BM2257 has more useful features/functions for my requirements. And the promotion/set does not seem to be available for the 116/117.I have no intention to do any mains works (nor microwave ovens!) - I know my limits and prefer to leave that work to the professionals.I will keep you posted once I have finally decided (may take a few weeks).Thanks again, your response time and helpfulness is really impressive!

author: tautech
author_rank: Super Contributor
timestamp: January 30, 2025, 12:05:35 am
content: Quote from: EEVblog on January 29, 2025, 11:34:35 pmApply KISS principles as to many new entrants a fuse isjusta fuse.

author: EEVblog
author_rank: Unknown
timestamp: January 30, 2025, 12:14:25 am
content: I forgot I had done this video!

author: bdunham7
author_rank: Super Contributor
timestamp: January 30, 2025, 01:22:01 am
content: Quote from: mwb1100 on January 29, 2025, 11:41:14 pmI just finished the first round with the fuses you sent me. You're right, it's not that exciting.

author: jj5
author_rank: Unknown
timestamp: January 30, 2025, 09:13:10 am
content: Quote from: mwb1100 on January 24, 2025, 11:11:08 pmI think that's a great idea. This set would suit me as I have a BM2257 and am planning to get 121GW and maybe some others. Not sure how much it would suit others though!

author: jj5
author_rank: Unknown
timestamp: January 30, 2025, 10:11:17 am
content: Quote from: jj5 on January 30, 2025, 09:13:10 amp.s. I would also be happy to buy one 11A+400mA set plus one 11A+630mA set.

author: Fungus
author_rank: Super Contributor
timestamp: January 30, 2025, 01:42:03 pm
content: Quote from: geralds on January 29, 2025, 10:10:45 pmEasily.

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: February 05, 2025, 11:48:34 pm
content: From the bm235-loz-mode thread:Quote from: EEVblog on January 24, 2025, 04:27:12 amWondering if anyone has anyone tested this? The user manual suggests LoZ only works down to 1.5V. Testing on mine it seems to work down to about 0.930V. If I'm not reading to much into the above quote it seems Dave is suggesting it goes all the way down to 0V? Or maybe he just meant that you get the full 1mV resolution until it cuts out, which it does. Not a big deal either way, but was curious if I was missing something.This is what the BM2257 user manual has to say about it.Quote

author: EEVblog
author_rank: Unknown
timestamp: February 06, 2025, 01:36:21 am
content: Quote from: CustomEngineerer on February 05, 2025, 11:48:34 pmI stand corrected. Just measured one and only got down to 0.93V.In practice, that's plenty low.

author: CustomEngineerer
author_rank: Frequent Contributor
timestamp: February 06, 2025, 05:14:01 pm
content: Agreed, thanks for verifying. Hope a few others do as well just to see if the 0.93V is consistent.

author: Furna
author_rank: Frequent Contributor
timestamp: February 06, 2025, 06:05:24 pm
content: I just received mine today ...I can go down to 0.928VThe image has been captured when it was at 0.929V but I can guarantee 0.928VSorry for the low quality photo.Super happy!Actually for the low amp fuse I went for EKSA 632.415 630mASorry Dave I didn't buy the fuse from you; at the time of the order you only had the 600mA

author: bdunham7
author_rank: Super Contributor
timestamp: February 06, 2025, 06:25:40 pm
content: Quote from: EEVblog on February 06, 2025, 01:36:21 amIt would be interesting to know what design quirk makes it work that way as I don't see an obvious reason for it on DCV. Is the input impedance still low below 0.93V?

author: EEVblog
author_rank: Unknown
timestamp: February 06, 2025, 10:46:03 pm
content: Quote from: Furna on February 06, 2025, 06:05:24 pmI've ordered 630mA fuses from ASTM but have not heard anything back yet. Resent the email to new people and still nothing. Not sure what's going on...

author: floobydust
author_rank: Super Contributor
timestamp: February 06, 2025, 11:22:43 pm
content: Quote from: bdunham7 on February 06, 2025, 06:25:40 pmWhat are we talking about? I got lost here.That there is a deadzone of +/-0.93V before a reading is displayed, or for the LowZ load to engage? The Brymen manual does not say what happens below "1.5V".You found the transistor clamp are in-series with the LowZ PTC load (on a different Brymen model) so nothing much is happening at below say 6V for the input impedance to decrease on them. (There may be a MOV-like action with these HV PTC's, as a faint theory of mine, as they have similar construction.)As far as the fuses go, I see very little difference from 500-630mA when the relevant BM2257 range is 600mA.Those fuses don't even consider blowing until currents are 2-4x times above that, and the i2t times are not so different.

author: bdunham7
author_rank: Super Contributor
timestamp: February 06, 2025, 11:41:40 pm
content: Quote from: floobydust on February 06, 2025, 11:22:43 pmWell, both and how they might be related. The BM2257 auto-ranges down and I'm really curious to know why it would not read below 0.93V just because there is a PTC across the inputs. I'm presuming it is because the input layout just isn't that simple. The input impedance issue is just another angle that might give a clue as to the input setup. It just seems a bit...weird.Fluke's straightforward approach means it will read down to the last digit in DC Lo-Z, although it only has a 1000V range. And the input impedance is about 3.2k no matter how little the input voltage is.

author: Furna
author_rank: Frequent Contributor
timestamp: February 07, 2025, 03:20:54 pm
content: Quote from: bdunham7 on February 06, 2025, 06:25:40 pmOhm's law says at 2V impedance is around 2KΩ (see picture).For lower voltages I get unreliable A values.

author: EEVblog
author_rank: Unknown
timestamp: February 07, 2025, 09:20:34 pm
content: Quote from: bdunham7 on February 06, 2025, 11:41:40 pmYeah, I'm surprised.I can understand the BM235 with the input arrangement it uses, but this is a bit puzzling. Sounds dual diode droppy...

author: floobydust
author_rank: Super Contributor
timestamp: February 07, 2025, 11:30:23 pm
content: If there is a deadzone for the LowZ to engage - then I'd need to know about it and probably say ick.It sounds like input impedance is 10MEGΩ when input voltage is less than 2-3 diode drops, and above that the PTC is present and 2.1kΩ when LowZ is selected. It does simplify the rotary switch design and that is why I think Brymen is doing it.To test/prove it you could inject a sine-wave with series sense resistor observed on a scope, to see if this is the case.This will cause a problem when troubleshooting low voltage such as automotive. You'll get say a 1.5V ghost reading outside of the pristine laboratory, in the mud and dirt.Do the armchair experts here know what this means?

author: bdunham7
author_rank: Super Contributor
timestamp: February 08, 2025, 12:17:15 am
content: Quote from: floobydust on February 07, 2025, 11:30:23 pmI don't think there's that sort of direct correlation between the input impedance and the minimum reading. Does the BM235 stop reading below about 7V or does it just go high-impedance? Those really are somewhat independent issues although the design may work in some sort of relation between the two. Dave just needs to break out a screwdriver and have a look....

author: EEVblog
author_rank: Unknown
timestamp: February 08, 2025, 12:43:58 am
content: Quote from: bdunham7 on February 08, 2025, 12:17:15 amIn progress...

author: Furna
author_rank: Frequent Contributor
timestamp: February 08, 2025, 09:59:57 am
content: One of the armchair experts here, doesn't have (yet) an AWG ... it's on the buy list althought not on the top.

author: floobydust
author_rank: Super Contributor
timestamp: February 08, 2025, 07:24:58 pm
content: It would be great if we knew the two PTC part numbers, somebody cut off the heatshrink tubing over them to see that.I also note Fluke ditched using clamp transistors for a while now in their newer models and instead is using diode arrays but they are not symmetrical. Clamp is +6Vfand -2Vfon the (PTC) Ohm's source channel and Dave might see something odd like that if Brymen is indeed running the LowZ PTC in series with a clamp.I could draw the BM2257 schematic if I had one or loosely based on board pics but that would cause trouble.Hey this is new silicon? Brymen got the (Hycon) LCD driver and DMM IC into one 100-pin package it seems.

author: bdunham7
author_rank: Super Contributor
timestamp: February 08, 2025, 07:48:23 pm
content: Quote from: floobydust on February 08, 2025, 07:24:58 pmFluke has newer models?The 87V does appear to be BAV199s. IDK about the small meters, but on the 289 it appears they just can't make up their mind which to use.

author: floobydust
author_rank: Super Contributor
timestamp: February 08, 2025, 08:59:07 pm
content: I consider the 87 an old dog, I love her dearly. Just a model number number Fortive keeps rehashing. That transistor clamp design goes back to at least 1989 in the Fluke 87, I don't consider it recent. Hand-selected parts and you don't know what their BVEBOends up, is it 5V or 7V or 10V etc. depending on batch and manufacturer.A 7V spike into a DMM IC is not really a good idea, still too much. The days of 9V battery-powered multimeter (IC's) are gone as well, today the IC's are lower voltage. People are just copying the old design I think.I was talking about for example, the Fluke 107 and 17B schematics. It's a diode party of BAV199, they must survive the few amp transient test impulse. The Fluke 107 Joeqsmith seemed to like its robustness, uses no transistor clamp scheme that I know of. (The 17B transistor clamp circuit is a bit over my head unless I get some coffee).BM2257 using SOT-23 diodes array? "N" marking code not sure what they are. Clamp transistors appear to be 2SC5866 "VLR" 6V but high leakage current.Hopefully Dave will reveal the Brymen LowZ issue at hand. 121GW is just a switch to engage the PTC, no drama.

author: Fungus
author_rank: Super Contributor
timestamp: February 08, 2025, 09:16:00 pm
content: Edit: Post removed - something mixed up in the system and that was about Uni-T.

author: floobydust
author_rank: Super Contributor
timestamp: February 08, 2025, 09:31:37 pm
content: Very few are 600V or 1,000V rated, and even fewer have approvals. Hard to find them and see their datasheets.

author: EEVblog
author_rank: Unknown
timestamp: February 08, 2025, 11:32:39 pm
content: Quote from: Fungus on February 08, 2025, 09:16:00 pmThe small one has no marking. I'll cut the heatshrink off the bigger one, but I suspect it's also unmarked.Brymen don't substitute parts that I know of, so they would have a specific brand and model specced in.

author: Fungus
author_rank: Super Contributor
timestamp: February 08, 2025, 11:46:49 pm
content: Quote from: mwb1100 on February 08, 2025, 10:49:41 pmPost removed - something glitched in the system. Of course Brymen don't buy Shenzhen specials.

author: EEVblog
author_rank: Unknown
timestamp: February 09, 2025, 05:10:59 am
content: Quote from: floobydust on February 08, 2025, 08:59:07 pmUnless I missed something in my reverse engineering, the LowZ input shunts PTC2 (bigger one, also unmarked under the heatshrink) and R32 (1K) directly to COM, and then going through R33 (1k) and PTC1 (smaller one), clamped with VAR2 and VAR1 to COM. Then through the HV 10M directly to pin 26 of the BTC chip. No extra protection.So anything that's happening here is happening inside the chip.The "VLR" SOT-23 clamps are only used in Ohms mode. Q10+Q11 in parallel with Q7+Q8.Edit: I missed the other side of the switch in Low-Z, but it wasn't in the input signal path, will trace it.

author: bdunham7
author_rank: Super Contributor
timestamp: February 09, 2025, 07:33:52 am
content: Can someone post a photo of their BM2257 in Low-Z mode with less than 0.928VDC on the input?

author: EEVblog
author_rank: Unknown
timestamp: February 09, 2025, 08:03:22 am
content: Quote from: bdunham7 on February 09, 2025, 07:33:52 amIt doens't display anything, just kinda flashed a bit IIRC, as if it was glitch reading or something.

author: bdunham7
author_rank: Super Contributor
timestamp: February 09, 2025, 08:07:04 am
content: Quote from: EEVblog on February 09, 2025, 05:10:59 amThat sounds like what I'd expect there to be and the impedance should be ~2.2k all the way to zero.I think maybe the answer is that the Auto-V switch logic that decides whether the display should be AC or DC may have a threshold or multiple thresholds. When you supply it with less than the 0.928V and it shows all zeros, does it display the AC or DC symbol? And where is the decimal point?Edit: our posts crossed in web continuumQuote from: EEVblog on February 09, 2025, 08:03:22 amSo an Auto-V threshold makes sense then. Next question: How low will it go on ACV @ 50/60Hz?

author: EEVblog
author_rank: Unknown
timestamp: February 09, 2025, 08:19:53 am
content: Quote from: bdunham7 on February 09, 2025, 08:07:04 amGood point, I'll try it.

author: EEVblog
author_rank: Unknown
timestamp: February 09, 2025, 08:56:33 am
content: Quote from: EEVblog on February 09, 2025, 05:10:59 amNope, it's just physically switching the backlight in OFF mode. Seems odd, maybe reducing quiescent, or maybe backfeeding through the chip during power down or something.

author: 5U4GB
author_rank: Super Contributor
timestamp: February 09, 2025, 02:30:13 pm
content: Quote from: Fungus on January 29, 2025, 09:09:17 pmIf it's a Chinese blade fuse you bought off Amazon, about 20 amps.

author: Furna
author_rank: Frequent Contributor
timestamp: February 09, 2025, 02:55:05 pm
content: Quote from: EEVblog on February 09, 2025, 08:19:53 amI measured 0.9 ACV @50Hz

author: kwass
author_rank: Frequent Contributor
timestamp: February 09, 2025, 03:12:09 pm
content: I get the same 0.900 V on 60Hz AC and a lower limit of 0.916 V on DC.BTW the AUTO DC volts is useful for testing small coin cells as the load is typical of many devices they are used in.

author: bdunham7
author_rank: Super Contributor
timestamp: February 09, 2025, 06:48:17 pm
content: Quote from: EEVblog on February 09, 2025, 08:19:53 amI think this "glitch", if it even can be called that, could likely becorrectedimproved in the firmware. I was curious as to how my only Auto-Check Low-Z meter, the Fluke 116, handles mixed signals or AC with a DC offset as well as small voltages--so I checked. It seems that the way the 116 handles it is to default to DCV (reads 0.0V DC with no input) and then measure and display the DC coupled RMS (aka TRMS AC + DC) value in all cases and either the AC or DC symbol depending on the mix. Again, it appears to default to DC and then only displays the AC symbol instead if the AC component is signficantly higher than the DC component. For example, 100mVAC and 200mVAC both display as 0.1 VDCand 0.2 VDCrespectively, while 300mV displays as 0.3VAC. I didn't test this extensively to see what the exact relationship was, but the AC component consistently needs to be significantly higher to get the AC displayed, at least at the lower levels. Perhaps at higher voltages the thresholds will be relatively closer.IDK how the Brymen system works internally and we probably will never know, but very possibly if they just had it default to DC whenever the inputs are low enough that the circuitry can't decide otherwise then it would read smoothly to zero. If these meters were really smart they would display both the AC and DC symbols when relatively significant components of either are present. But maybe they just ran out of program memory space.....

author: floobydust
author_rank: Super Contributor
timestamp: February 09, 2025, 11:15:31 pm
content: I drew a partial schematic of the BM2257 front-end and also agree, the (bigger) PTC2 get's grounded in LowZ mode (at S0B1) - not like some other BM235? I think that left the clamps in series which is what I was on about for the input impedance being two levels.The only other DMM I know about with a deadzone is the AN8008 around +/-4uV it truncates to 0V to mask A/D noise.I think here, for the BM2257 it might be for the superstitious multimeter users that freak out when it doesn't read zero?Something else I noticed is some sloppy PCB layout again on the rotary switch rings. It's like the layout guy has 1 hour to pound this out lol.The change to using four MOV's is also to save space.

author: EEVblog
author_rank: Unknown
timestamp: February 10, 2025, 12:24:08 am
content: Quote from: floobydust on February 09, 2025, 11:15:31 pmYes, the BM235 goes into a transistor zener clamp, hence will only conduct the PTC once it hits 7V or so. Interestingly, the BM235 does actually go lower than the BM2257 in LowZ, down to 0.5VQuoteYes, looks rushed! Didn't bother to reshuffle things when they they ran out of space, so added a bodge wire around the socket, a 10A jumper cable on the top, and a battery wire on the bottom.

author: EEVblog
author_rank: Unknown
timestamp: February 10, 2025, 06:40:00 am
content: My reverse engineered partial schematic, could have errors, stuff missing, but shows how it works.Video to be released in the next few days:

author: Kleinstein
author_rank: Super Contributor
timestamp: February 10, 2025, 10:38:55 am
content: In normal operation there are 3 MOVs in series at the input. In low Z mode there are only 2 MOVs in series (VAR1+VAR2). So one may have a slightly earlier clamping, lower maximum voltage in low Z mode.The loading part in low Z mode is just the resistor and PTC (looks like the same as for the ohm mode). There should be no good reason for a lower voltage limit in the low Z mode. There is just the point that the AC detection has a lower limit to detect AC.

author: EEVblog
author_rank: Unknown
timestamp: February 10, 2025, 01:10:47 pm
content: Quote from: Kleinstein on February 10, 2025, 10:38:55 amIt's still 1240V, above the max rating of the meter.

author: bdunham7
author_rank: Super Contributor
timestamp: February 10, 2025, 04:38:43 pm
content: Quote from: Kleinstein on February 10, 2025, 10:38:55 amThose MOVs are rated for 385VAC continuous, the lower "extra" MOV is 350VAC. IDK for sure why they've added that lower MOV, but if the reason was to reduce leakage and keep the input resistance at 10M even at the maximum input voltage then that need would not apply to the Low-Z mode. Another possibility is that the 4-MOV setup is a leftover design feature from a previous version that had the now prohibited 'CAT II/1000V' rating and now at CAT III/600V they don't need it but didn't bother to take it out.

author: floobydust
author_rank: Super Contributor
timestamp: February 10, 2025, 08:03:57 pm
content: Quite high voltage MOV's are not available in the small 5mm size. Fluke went with their custom Epcos S05K575 (575VRMS) 910V@1mA.I see Brymen simply used two in series to get the same net clamping voltage in 5mm size, using off the shelf parts.(625VRMS) 1,000V@1mA is a 10mm part, one used in predecessors BM235, BM786 etc. with a smaller 7mm in series.You want the smallest size part for cost, low capacitance but big enough to pass the 61010 transient test which is a few amp spike.Leakage current looks high I'm not sure if anyone has actually measured it at max. input voltage say 1,000VDC or 600VAC to see if is an unknown issue.Clamping voltage I estimate is max. ~3,000V total in a few amp transient. joeqsmith has the data.

author: bdunham7
author_rank: Super Contributor
timestamp: February 10, 2025, 08:28:35 pm
content: Quote from: floobydust on February 10, 2025, 08:03:57 pmWith three in a row at 600V, that's 200V apiece and extrapolation puts that leakage current at a fraction of a µA. At 600V a 10M input would have 60µA already, so not an issue. With only two, the leakage current would be higher but in Low-Z mode your input impedance is probably less than 1M @ 600V and your current is >600µA and not very stable or certain anyway.

author: Furna
author_rank: Frequent Contributor
timestamp: February 10, 2025, 08:29:30 pm
content: Quote from: floobydust on February 10, 2025, 08:03:57 pmWhile reading the last few posts, I thought it is time someone send a BM2257 to joeqsmith.After Dave's video, we can get one more interesting video.

author: EEVblog
author_rank: Unknown
timestamp: February 10, 2025, 09:47:07 pm
content: Quote from: floobydust on February 10, 2025, 08:03:57 pmI forgot the datasheet link:https://www.cnr.com.tw/cloudSpace/CNR_D.pdfWill test the leakage @1000V

author: tautech
author_rank: Super Contributor
timestamp: February 10, 2025, 09:48:41 pm
content: Quote from: Furna on February 10, 2025, 08:29:30 pmNot just yet.....there might be a revision like there was with the GW.......

author: EEVblog
author_rank: Unknown
timestamp: February 10, 2025, 11:06:15 pm
content: Tested.TLDR; Not a problem at 1200V DC and 1100V AC

author: Furna
author_rank: Frequent Contributor
timestamp: February 10, 2025, 11:17:08 pm
content: Quote from: EEVblog on February 10, 2025, 11:06:15 pmWatch the typo ... 1000V DC

author: bdunham7
author_rank: Super Contributor
timestamp: February 10, 2025, 11:24:17 pm
content: Whoa...wait! It has an undocumented 6000V range?

author: EEVblog
author_rank: Unknown
timestamp: February 10, 2025, 11:55:07 pm
content: Quote from: bdunham7 on February 10, 2025, 11:24:17 pmIn theory yes, try it

author: geralds
author_rank: Contributor
timestamp: February 11, 2025, 01:04:00 am
content: Not just yet.....there might be a revision like there was with the GW.......Would that be a FW update? If so, is it now possible to update the FW oneself (i.e. without sending it in for service)? I understand this was (generally) not possible with other Brymens?Also (and again, apologies for such a Newbie query - I am a complete beginner and trying to learn...): How relevant is the LoZ "issue" for LV/electronics? In practice, would you use LoZ mode for electronics / hifi repair works?Thanks!

author: EEVblog
author_rank: Unknown
timestamp: February 11, 2025, 01:13:26 am
content: Quote from: geralds on February 11, 2025, 01:04:00 amOnly the BM780 series is designed for firmware updating. But even then the user can't do it, only a Brymen dealer who has access to the programming tool.QuoteIt's mainly for mains ghost voltage elimination, but there are niche uses for lower voltage work. For repair it's useful for safely discharging capacitors. But I have a video on that:

author: Kleinstein
author_rank: Super Contributor
timestamp: February 11, 2025, 08:47:16 am
content: The current specs for the MOVs are maximum values. As typical for leakage currents the actual value is often much better than the specs.For those 200 Mohms range effective resistance already surface contaminations could be an issue.The slightly higher current in the AC test can come from parallel capactance. The input impedance is not just the 10 M ohms, but also has a few pF of parallel capacitance inside the meter and also the cables outside. So I don't think it is leakage at the MOVs, more like the capacitance of the MOVs.

author: dkarst
author_rank: Newbie
timestamp: February 12, 2025, 03:34:03 pm
content: I've been following this thread and don't think I've seen anything mentioned on the BM789. It has been on the market with Low-Z capability (one if its key differences from EEVblog BM786). I believe the spec for it is Low Z functionality with input < 1 volt. I don't know if anyone here has looked at the input circuit topology. Possibly, since the new BM2257 has this behavior at 0.9X volts, Brymen noted the behavior and made the spec <1V. Maybe for the BM2257 they wanted to have a bit more headroom from spec and changed it to 1.5V. It may also have a totally different input.I guess just speculating since I don't have a BM789. Just hadn't seen it discussed and thought interesting.

author: EEVblog
author_rank: Unknown
timestamp: February 12, 2025, 08:30:35 pm
content: Quote from: dkarst on February 12, 2025, 03:34:03 pmWelcome to the forum. I'd bet it's the same arrangement as the BM2257.

author: J-R
author_rank: Super Contributor
timestamp: February 12, 2025, 10:22:02 pm
content: My BM789 bottoms out at exactly +/- 0.9000V DC in Auto V/LoZ mode.

author: 5U4GB
author_rank: Super Contributor
timestamp: February 13, 2025, 02:50:13 am
content: Quote from: EEVblog on February 11, 2025, 01:13:26 amI was recently doing some alarm re-wiring and there were ghost voltages everywhere, I wanted to use an NCV to check which sensor was wired to which input and it was impossible, almost every sensor registered a voltage present when disconnected. As did the mains input to the alarm even though it was disconnected at the switchboard.Really tempted to get a BM2257 now, I'd always considered Low-Z a bit of an extravagance (given the cost of the meters it came with), but after the recent episode...

author: floobydust
author_rank: Super Contributor
timestamp: February 13, 2025, 03:41:09 am
content: LowZ is a must have. Digital multimeters are too sensitive out in the real world - you'll get ghost readings due to capacitive AC coupling of mains, as well as DC leakage currents due to moisture and corrosion. Unless you have an analog VOM lol. 10MEG input impedance or higher leads to goose chases, I've been burned a few times troubleshooting.

author: xKertx
author_rank: Regular Contributor
timestamp: February 15, 2025, 12:54:05 pm
content: Does it have an option in it's settings that let's you choose whether you use normal alkaline batteries or Ni-Mh rechargeable ones?Some quality meters have it (my Keysight multimeter and Vaisala thermo-hygrometer both have it) and i think it's a really nice feature. The low battery warning would be more accurate and you will not overdischarge/destroy your rechargeables.

author: Furna
author_rank: Frequent Contributor
timestamp: February 15, 2025, 03:38:04 pm
content: Quote from: xKertx on February 15, 2025, 12:54:05 pmShort answer: no, there is no such setting.Anyway in the general specifications at pag. 17 of the manual you can find the "Low Battery" voltage below approx 2.5V (so 1.25V each cell).AFAIK lowest safe voltage for Ni-Mh is 0.9V.IMHO perfectly safe to use Ni-Mh but (very) short duration since max for Ni-Mh is 1.42V and nominal 1.2V.

author: Kleinstein
author_rank: Super Contributor
timestamp: February 15, 2025, 03:55:41 pm
content: Showing low Bat at 1.25 V is a bit on the high side for NiMH or NiCd. That is arealy above the 1.2 V nominal voltage.The problem is not the maximum voltage - that can be at some 1.6-1.7 V, similar to very new alkaline cells.The point is that the meter could show low battery when NiMH is still 95% full.

author: xKertx
author_rank: Regular Contributor
timestamp: February 15, 2025, 03:57:36 pm
content: Well the nominal voltage of the Ni-Mh is 1,2V when there is about 60% charge left. So that 1,25v threshold means you get the low battery warning all the time and eventually ignore it and have to guess when the batteries need to be charged.It's little dissapointing because other than that it seem like a really nice DMM. I like to use ni-mh in my better equipment to avoid leakeage problems.I wish Dave could give them a hint and maybe they could add it to future firmware versions.

author: Furna
author_rank: Frequent Contributor
timestamp: February 15, 2025, 04:00:40 pm
content: I guess there is also a cut-off min voltage ... so it is not that you get the low battery and ignore it ... the meter will shutdown.What is the cutoff voltage? I have no idea.

author: bdunham7
author_rank: Super Contributor
timestamp: February 15, 2025, 04:30:39 pm
content: Quote from: Kleinstein on February 15, 2025, 03:55:41 pmThat depends on load. The open-circuit voltage for a NiMH battery is almost always above 1.2 and usually even 1.25V after use at light loads. Even at 50mA load on an AA cell, a 1.25V cutoff would yield more than 2/3 of the total capacity of the battery. Most reasonable handheld multimeters will have a battery load much less than 50mA. The ones that use 9V batteries can be below 1mA.https://citeseerx.ist.psu.edu/document?repid=rep1&type=pdf&doi=5edecfd325c3787e2dd76a7460005bf5abe1758f

author: Furna
author_rank: Frequent Contributor
timestamp: February 15, 2025, 04:42:28 pm
content: Test leads shorted and selector on Continuity/Beeprstill working at 1.77V (drowing 25mA)shutdown at 1.76Vso 0.88 each cellI would say safer for Ni-Mh ...Anyway there must be a reason why Brymen choose 2.25V for low batt ... usually to guarantee reliable results.Measurement done with a PSU

author: Fungus
author_rank: Super Contributor
timestamp: February 15, 2025, 05:32:23 pm
content: Anybody got any Batterizers?

author: mwb1100
author_rank: Frequent Contributor
timestamp: February 15, 2025, 08:53:15 pm
content: NiMH has a flatter voltage/discharge curve than alkaline, so the low battery behavior might be OK.Has anyone experience with using NiMH in the BM257s which is specified to show low battery when below 2.3V (no surprise that it's basically the same as the BM2257)?

author: xKertx
author_rank: Regular Contributor
timestamp: February 15, 2025, 09:24:52 pm
content: Quote from: mwb1100 on February 15, 2025, 08:53:15 pmYes, at low discharge currents the NiMh voltage is 1,2V most of the time, until it is almost depleted and the voltage drops.The 2,5V threshold for the low battery warning is too high because the batteries will be half of the time below that.2,3v (like on the bm257) would be much better because it would be below the NiMh's nominal voltage.

author: mwb1100
author_rank: Frequent Contributor
timestamp: February 15, 2025, 09:57:09 pm
content: Quote from: xKertx on February 15, 2025, 09:24:52 pmYes - I got lost about what the low battery threshold for BM2257 is... too many numbers between 1.2 and 2.5V being thrown around here for my feeble mind to keep track.

author: 5U4GB
author_rank: Super Contributor
timestamp: February 16, 2025, 07:10:29 am
content: An alternative you can use, at the cost of slightly shorter times between recharges, is LiFePO4 batteries instead of NiMH. This requires battery compartments which use cells in multiples of 2, since you're putting a LiFePO4 in series with an empty head (battery spacer that doesn't do anything), with the total having a combined voltage of the LiFePO4's 3.2V, equivalent to two fresh nominal-1.5V cells.The other slight problem is that most standard chargers won't charge them, you'd need something like an MC3000 and even then it's not one of the standard charge programs.

author: EEVblog
author_rank: Unknown
timestamp: March 19, 2025, 11:18:26 pm
content: FYI I split out the BM235 display lag/pause issue here:https://www.eevblog.com/forum/testgear/brymen-bm235-multimeter-display-lagpause/

author: eematt
author_rank: Newbie
timestamp: March 20, 2025, 12:31:07 am
content: Quote from: EEVblog on September 12, 2024, 06:27:49 amHi Dave, thank you for sponsoring this meter as it checks a lot of boxes in a great form factor!Regarding the backlight color, I personally view the orange backlight as jarring and almost cringey with the EEV blue and remaining monochromatic hue of the meter with the black body, gray buttons, and white silkscreening. I appreciate that: everyone has their own personal perspective, the orange might offer better contrast, and that white LEDs need more voltage to drive than orange. However, I suspect the majority of potential buyers would prefer a white backlight as it tends to present cleaner and more modern than legacy colors, the potential extra amount of contrast is insignificant, and driving a white backlight is possible with two AAAs as it’s EEV predecessor ( BM235 ) does exactly that.I am curious to know if you are planning on keeping the orange backlight? Or are you open to the idea of investigating a white backlight, or have existing plans to change the backlight color?For the potential future EEV store multimeter model lineup, I recommend not offering both the BM235 and BM2257. The BM2257 is essentially just a better BM235 minus some insignificant details not relevant the target buyer pool. And, the price point is only marginally more making it the clear choice regardless of budget allowance.Thanks, long time viewer ( ~14 years ), first time poster.Matt

author: EEVblog
author_rank: Unknown
timestamp: March 20, 2025, 12:50:14 am
content: Welcome.Quote from: eematt on March 20, 2025, 12:31:07 amYou are the only one who has complained about it that I know of.QuoteYes.QuoteNo, I like the orange.QuoteIf people keep buying it I'll keep selling it.

author: J-R
author_rank: Super Contributor
timestamp: March 20, 2025, 05:09:14 am
content: I mentioned on page 1 of this thread that I also prefer white or the blue-tinted white along with the EEVblog blue color, as well as that the BM2257 is based on the BM257, and the BM2251 the BM251. So not the BM235. They've also released the BM2800CSE series (CAT and shielded enhanced), which appears to be an updated version of the BM800s line.Who knows why Brymen selects one color over the other. The BM805s & BM806s have white, while the BM807s is orange, and the BM2800CSE series are all orange.Furthermore, the BM251 has a white backlight while the BM2251 has orange. Perhaps orange is the new white.There were some Brymen-red BM2257 units available a while back, but I haven't seen any lately other than from Telonic, but they don't ship to the US.

author: bdunham7
author_rank: Super Contributor
timestamp: March 20, 2025, 05:16:38 am
content: Quote from: EEVblog on March 20, 2025, 12:50:14 amThat is Fluke's entire marketing plan!

author: EEVblog
author_rank: Unknown
timestamp: March 20, 2025, 05:46:42 am
content: Quote from: bdunham7 on March 20, 2025, 05:16:38 amIt works.

author: EEVblog
author_rank: Unknown
timestamp: March 20, 2025, 05:50:22 am
content: Quote from: J-R on March 20, 2025, 05:09:14 amThat would be my guess, they prefer orange for new models for some reason.Companies change colour all the time, like the recent black trend from the big test equipment makers.There is a new model Brymen that I'll be carrying soon, I don't know what colour it has yet, will be interesting to see.

author: rsjsouza
author_rank: Super Contributor
timestamp: March 20, 2025, 11:08:25 am
content: I have a Greenlee DM-200A (BM251 equivalent) and its orange color suits well its display.Since everyone has opinions, I personally prefer the orange to white - to me it is easier on the eye, but perhaps my opinion might be skewed by the plethora of white backlights on the cheaper models these days. Perhaps that is why Brymen is moving away from pure white - distance from the flooded market.

author: TomKatt
author_rank: Frequent Contributor
timestamp: March 20, 2025, 11:33:52 am
content: I'm too lazy to look - does this new meter have the flashing continuity?I've got a Greenlee DM820A (rebranded BM869s?) that is a fantastic meter, but I much prefer the continuity on Dave's BM235... It's just so easy to see the display in a loud production floor environment.Also, I do prefer orange to white. I'm not a fan of blue led's no matter what temp you call them.EDIT - got off my butt and looked lol. Yup, has 'BeepLit' technology lol. Looks like a nice meter.

author: mwb1100
author_rank: Frequent Contributor
timestamp: March 20, 2025, 02:09:22 pm
content: White, orange, whatever. I just want the backlight to last more than 30 seconds. 2 minutes is good, more is better.Quote from: EEVblog on March 20, 2025, 05:50:22 amOh no! I'm trying to cut back!Quote from: EEVblog on March 20, 2025, 05:50:22 amIf it's not blue, eevblog will explode!

author: TomKatt
author_rank: Frequent Contributor
timestamp: March 20, 2025, 02:19:20 pm
content: [ Specified attachment is not available ]Quote from: mwb1100 on March 20, 2025, 02:09:22 pmLOL - I Googled BM2257 and the 2nd result is the EEVblog forum discussion on the meter and the 3rd result is Dave's store listing for it... I didn't realize he was selling these already. I live under a rock - the temperature and humidity are constant year roundEdit - moved to 1st and 2nd place,... Google must be user specific? Damn privacy invading cookies![ Specified attachment is not available ]

author: AVGresponding
author_rank: Super Contributor
timestamp: March 20, 2025, 06:28:45 pm
content: Quote from: rsjsouza on March 20, 2025, 11:08:25 amEither that, or copying Keyshite

author: Sebekh
author_rank: Newbie
timestamp: March 20, 2025, 09:03:35 pm
content: Dave can you tell me more about the new brymen multimeters. I wish they would add the 2257 features to my favorite bm857s. The 86x 82x 83x series is too big for me

author: TomKatt
author_rank: Frequent Contributor
timestamp: March 20, 2025, 10:47:49 pm
content: The data sheet and manual are posted on the bottom of Dave’s store page…https://eevblog.store/products/eevblog-bm2257-multimeter?srsltid=AfmBOooVrrpdOzbQPKy9aR6gUWLshmoVVCP7ufXZ2pk77JaGvTKEpg3W

author: EEVblog
author_rank: Unknown
timestamp: March 21, 2025, 12:06:37 am
content: Quote from: Sebekh on March 20, 2025, 09:03:35 pmI'm not sure if they want me to say anything, but it's been something long promised.

author: Sebekh
author_rank: Newbie
timestamp: March 21, 2025, 10:35:21 am
content: Dave, can you at least tell us when we can expect some news?

author: EEVblog
author_rank: Unknown
timestamp: March 21, 2025, 10:03:48 pm
content: Quote from: Sebekh on March 21, 2025, 10:35:21 amI've asked them that and they haven't replied yet.The pre-release unit is on the way to me now.

author: 5U4GB
author_rank: Super Contributor
timestamp: March 22, 2025, 08:45:47 am
content: Was going to ask the same thing, I've been sitting on the fence about getting a 2257 but wondering whether I should wait. Are you allowed to reveal whether it'll be around the same price as the 2257?

author: EEVblog
author_rank: Unknown
timestamp: March 22, 2025, 09:33:09 am
content: Quote from: 5U4GB on March 22, 2025, 08:45:47 amMore expensive than the 121GW actually, unless I eat some of the margin.

author: VitalyCo
author_rank: Newbie
timestamp: March 23, 2025, 05:59:15 pm
content: Quote from: EEVblog on March 22, 2025, 09:33:09 amHopefully Ni-MH will be considered a first class citizen in this model.

author: EEVblog
author_rank: Unknown
timestamp: March 23, 2025, 10:21:10 pm
content: Quote from: VitalyCo on March 23, 2025, 05:59:15 pmIt will be no different to the 786.

author: mwb1100
author_rank: Frequent Contributor
timestamp: March 23, 2025, 11:27:47 pm
content: Quote from: EEVblog on March 22, 2025, 09:33:09 amJust to alleviate any concern you might have, we don't mind if you want to eat some margin.

author: Sebekh
author_rank: Newbie
timestamp: March 26, 2025, 03:23:52 pm
content: Hi Dave I have a request could you compare the crest function in 2257 with another bm7xx or bm8xx and present it on YouTube I think it will be interesting I think brymen is the only one that has this function. And the question is did the new multimeter arrive?

author: J-R
author_rank: Super Contributor
timestamp: March 26, 2025, 11:03:28 pm
content: Not sure if it was stated specifically previously, but the BM2257 PCB has markings for: 2251, 2253, 2255, 2256, 2257 & 2258. Byrmen currently only has the BM2251 and BM2257 listed in their datasheet.

author: mwb1100
author_rank: Frequent Contributor
timestamp: March 26, 2025, 11:18:54 pm
content: Quote from: Sebekh on March 20, 2025, 09:03:35 pm@joeqsmithhas posted about a new Brymen model (BM788BT) along with a link to a video here:https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg5860739/#msg5860739It seems this (or an eevblog variation) is the new meter Dave alluded to.

author: bte
author_rank: Regular Contributor
timestamp: March 26, 2025, 11:29:12 pm
content: Quote from: mwb1100 on March 26, 2025, 11:18:54 pmIt is...https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg5860759/#msg5860759

author: EEVblog
author_rank: Unknown
timestamp: March 27, 2025, 12:20:16 am
content: Quote from: J-R on March 26, 2025, 11:03:28 pmThey do that for customers who want to brand their own slightly different model. e.g. me with the BM786, it had a slightly different feature set so I took the available BM786 number.And the new BM780BT series, I have the BM787BT

author: EEVblog
author_rank: Unknown
timestamp: March 27, 2025, 12:21:05 am
content: Quote from: mwb1100 on March 26, 2025, 11:18:54 pmYes, new thread here:https://www.eevblog.com/forum/testgear/new-brymen-bluetooth-bm787bt-multimeter/

author: Sebekh
author_rank: Newbie
timestamp: March 27, 2025, 09:14:17 am
content: Hi Dave I have a request could you compare the crest function in 2257 with another bm7xx or bm8xx and present it on YouTube I think it will be interesting I think brymen is the only one that has this function.I think You have the equipment and knowledge to do it well if You have the time

author: J-R
author_rank: Super Contributor
timestamp: March 27, 2025, 09:47:15 am
content: Quote from: EEVblog on March 27, 2025, 12:20:16 amYes, I knew this but still found it quite interesting that they had so many listed. They must be dreaming big with this model...

author: puxe
author_rank: Contributor
timestamp: March 27, 2025, 09:55:37 am
content: I suspect this 'Crest' function is the same as the 'Peak' function on my recent "NJTY T58C 9999 Counts Inductance Digital Multimeter".Yet another inexpensive meter, but I like it, with the auto backlight and illuminated jack sockets etc. it also has pretty fast continuity responsive, when I use with cheap gold/ silicone leads ( PT1032 £3). It seems accurate enough and has a level of fused inputs, sufficient for electronics. This model also provides Inductance testing, which did give a reasonable value on the limited testing I did.Just mentioned because 'Peak' function is not all that common; TBC if it works as expected as I haven't tried it.

author: J-R
author_rank: Super Contributor
timestamp: March 27, 2025, 10:28:16 am
content: There is a bit of information in the manuals about the "CREST mode (Instantaneous Peak Hold)" feature:BM225x:Current or Voltage peak values in durations as short as 5msResolution: 6000 countsSpecified accuracy +/- 100 digits for changes > 0.35ms in durationAvailability: Voltage and Current functionsBM78x:Current or voltage peak values in duration as short as 0.25msResolution: 6000 countsAdd ± 250 digits to specified accuracy for changes in duration> 1ms for VFD-ACV function;> 350μs for other Voltage and Current functions

author: puxe
author_rank: Contributor
timestamp: March 27, 2025, 10:40:28 am
content: That's interesting.I'm not at home for a month and don't have the paper manual for the NJTY meter. Can't find any online copy either for it (or the Richmeters equivalent).The logic must be that there is a distinction between Max/Min function and Peak, which is of short duration.Obviously a scope would be more suitable, but I guess if the short duration matches the peak, this would be a suitable method to capture the peak event.

author: 5U4GB
author_rank: Super Contributor
timestamp: March 27, 2025, 11:49:37 am
content: Quote from: Sebekh on March 27, 2025, 09:14:17 amAFAIK only Brymen call it that but a lot of other meters have it too, with names like Peak and Max Hold. For example the Klein MM720, with specs and features very similar to the 2257, has MIN/MAX buttons for this - the reason I mention that one specifically is because it's a toss-up between that and the 2257 given their feature and price similarity. Of course the Klein one isn't blue...

author: puxe
author_rank: Contributor
timestamp: March 27, 2025, 01:26:54 pm
content: Are you sure the Klein Max/Min function has the additional 'peak/crest' short duration functionality and not just 'normal' max/min capture like many other meters?Edit.... I just downloaded the MM720 manual and it looks like simple max/min functionality with my quick look

author: Sebekh
author_rank: Newbie
timestamp: March 27, 2025, 03:45:35 pm
content: well not every dmm is that fasthttps://youtu.be/cMSuF_RdgW0?feature=shared

author: mwb1100
author_rank: Frequent Contributor
timestamp: March 27, 2025, 05:28:41 pm
content: Brymen's crest function shows the max/min of the AC waveform, not the max/min of the AC RMS value. Getting the max/min (and sometimes avg) value of the RMS AC is done with the "REC" button. Brymen's REC function is more commonly called "MAX/MIN" - I think that some Brymen meters also use that label, but for some reason they seem to prefer "REC".See photos for what the CREST function shows on a line with AC RMS 118.3V. Theoretically the CREST value should be 1.414 times the RMS value.

author: shapirus
author_rank: Super Contributor
timestamp: March 27, 2025, 09:04:19 pm
content: Quote from: mwb1100 on March 27, 2025, 05:28:41 pmThat looks quite right. The mains sine wave often has somewhat flattened tops these days.It may be interesting to cross-check this with an oscilloscope.What will be much more interesting, though, is to compare Crest mode measurements with oscilloscope captures for short pulses, especially as short as the durations specified in the manual and shorter.

author: bdunham7
author_rank: Super Contributor
timestamp: March 27, 2025, 10:16:13 pm
content: Quote from: 5U4GB on March 27, 2025, 11:49:37 amI thought it was confusing too. The only other meter I can recall seeing the term "crest" used is my Fluke 289 which has a "crest factor" function--but that displays the actual crest factor, as in "1.4" for my mains voltage. The upper and lower peak of the mains is given by the peak function in either the AC or DC ranges.

author: 5U4GB
author_rank: Super Contributor
timestamp: March 28, 2025, 09:03:05 am
content: Quote from: puxe on March 27, 2025, 01:26:54 pmYeah, I don't have a 2257 (yet) so had assumed it was everyone else's MAX, however looking at the manual it looks like Brymen hide their MIN/MAX behind R(ecord). However also from the manual, CREST also indicates as MIN/MAX:QuoteIn terms of ease of use I'd say I rather prefer the Klein UI, the Brymen one looks too much like anAPL keyboardtransferred to a multimeter. But as I said earlier, the Klein isn't blue :-).

author: EEVblog
author_rank: Unknown
timestamp: March 28, 2025, 10:25:09 pm
content: Quote from: mwb1100 on March 27, 2025, 05:28:41 pmCrest mode is, from the manual, "Instantaneous PEAK-HOLD" to capture current or voltage peak values in duration as short as 0.25msThey advertise it for uses like measuring in-rush current for example.Interestingly I gave Mehdi from Electroboom a BM2257 the other day (he's was in Sydney) and he saw the REC button and assumed it was a data logging record function, I had to explain it was Brymen version of MIN/MAX mode.This is on the walkaround video we did.https://youtu.be/EIszL6M8CiI?si=6G7AZwz0VjQvltoo&t=2610

author: 2X
author_rank: Frequent Contributor
timestamp: April 10, 2025, 09:41:07 pm
content: Hi guys, do you know if this multimeter is available on european store like welectron?

author: Furna
author_rank: Frequent Contributor
timestamp: April 10, 2025, 09:45:16 pm
content: Quote from: 2X on April 10, 2025, 09:41:07 pmWelectron never listed it on their web site; TME.EU did but currently has 0 in stock.Personally bought one from Dave's shop and had 0 issue.

author: EEVblog
author_rank: Unknown
timestamp: April 11, 2025, 01:32:40 am
content: Quote from: Furna on April 10, 2025, 09:45:16 pmI have a ton of stock.Use coupon code orderofmagnitude for 10% off.

author: 5U4GB
author_rank: Super Contributor
timestamp: April 11, 2025, 07:53:38 am
content: Quote from: EEVblog on April 11, 2025, 01:32:40 amThanks, just ordered one!

author: 2X
author_rank: Frequent Contributor
timestamp: April 11, 2025, 09:40:55 pm
content: Quote from: EEVblog on April 11, 2025, 01:32:40 amThanks Dave.

author: 5U4GB
author_rank: Super Contributor
timestamp: April 12, 2025, 10:58:40 am
content: Quote from: 5U4GB on April 11, 2025, 07:53:38 amA followup question, I've just had an email telling me:QuoteHowever with something magical known as aTracking NumberI can also track the order without having to install someone's custom app to do it. Is this just Shop being pre-emptive to get me to install their app?

author: Furna
author_rank: Frequent Contributor
timestamp: April 12, 2025, 11:02:03 am
content: Quote from: 5U4GB on April 12, 2025, 10:58:40 amI was able to track without installing anything ... unfotunately I cannot recall where I spotted the tracking number.

author: mwb1100
author_rank: Frequent Contributor
timestamp: April 12, 2025, 03:49:49 pm
content: Quote from: 5U4GB on April 12, 2025, 10:58:40 amWhen the package ships you'll get an email from sales@eevblog.com with a URL that has a tracking number.

author: EEVblog
author_rank: Unknown
timestamp: April 13, 2025, 03:31:49 am
content: Quote from: mwb1100 on April 12, 2025, 03:49:49 pmCorrect, that's just Shopify trying to spruik their app, you don't need it.

author: EEVblog
author_rank: Unknown
timestamp: April 13, 2025, 03:52:01 am
content: Quote from: 5U4GB on April 12, 2025, 10:58:40 amJust processed it, you should now have the tracking number.

author: 5U4GB
author_rank: Super Contributor
timestamp: April 13, 2025, 06:34:19 am
content: Quote from: EEVblog on April 13, 2025, 03:31:49 amNo worries, figured it might be that :-).

author: HKJ
author_rank: Super Contributor
timestamp: May 09, 2025, 03:23:52 pm
content: This meter is now supported by TestController.Thread:https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/Download:https://lygte-info.dk/project/TestControllerIntro%20UK.htmlThe meter can be used on Windows, Linux and Mac. The interface is a two part interface, first part is from DMM to DB9 serial connector, second part is a serial to USB adapter, both are included in the Brymen serial kit.Here is an example of recording mains voltage Actual sample rate was 1/sec, i.e. I can zoom/search in on details):Bottom of table:64000 samples over 17 hours is easy for TC, it can handle much larger samples sizes and longer times.It is possible to connect multiple meters to TestController and do calculations on the values, save csv files and do some large readouts on a computer. TC can also calculate the same statistic as a bench meter.

author: JamesE
author_rank: Newbie
timestamp: May 18, 2025, 05:01:06 am
content: Hey fellas, hey Dave, forum newbie here. I've been doing digital PCB designs for a few years and the best multimeter I have is a mid-1990's model (apparently a Nilsen BX-905AC....Australian company but it may be just a re-brand). The BM2257 looks like a great mid-ranger, I figure that going to a 121GW or upcoming BM787BT would be overkill for my purposes. Even just a readable screen would be a big improvement, considering that mine has no backlight and the LCD has some serious screen burn so the characters are hardly visible. Certainly overdue for an upgrade.

author: EEVblog
author_rank: Unknown
timestamp: May 18, 2025, 07:24:23 am
content: Quote from: JamesE on May 18, 2025, 05:01:06 amWelcome to the forum.Yes the BM2257 will be a nice upgrade, it's has a big readable screen, and unless you need the extra resolution or accuracy the 121GW or BM786/787 could be overkill.

author: jebem
author_rank: Regular Contributor
timestamp: July 18, 2025, 06:06:40 pm
content: I guess I am a bit late for the show, but I had to get this BM2257 DMM no matter what.I have been collecting the cheapest and not so cheaper DMMs on AliExpress from well known Chinese brands.Strangely enough I never cared to buy one from Brymen or even from UNI-T.Having worked with Fluke DMMs at my job for years, at home any cheap meter would do.After checking so many EEVBlog equipment reviews (Thank you, Dave!) and discussions (Thank you, all members!), I decided that I needed one properly designed and built DMM for home usage.Then I discovered that Brymen seems to be too busy doing other tasks to allocate time to restart producing this model.I simply could not find a single European distributor/seller with a non zero stock.I hesitate to order outside European Union due to potential difficulties when clearing Customs bureaucratic procedures. It goes like this:After getting a registration/tracking code for the package, I must register it at my Portuguese CTT courier website, in order to be able to pay the VAT and Custom duties.But in the end, I decided to not wait any longer and have just ordered one BM2257, a Case and a BRUA-20X USB Serial Interface from EEVBlog Store.Now it is waiting time for delivery...

author: BILLPOD
author_rank: Frequent Contributor
timestamp: July 18, 2025, 06:23:39 pm
content: Good Morning Jebem, Congratulation on your choice. Brymen meters are some of the best out there. I have the BM869S, and LOVE it. I'm sure you will be happy with your purchase. After you have had time to put your new meter through it's paces, come back here and tell us your opinion. Thank you Jebem

author: jebem
author_rank: Regular Contributor
timestamp: July 18, 2025, 07:57:59 pm
content: Quote from: BILLPOD on July 18, 2025, 06:23:39 pmThank you for your reply.The 869 seems to be one of the high end models, very impressive!I am sure I will not be disappointed with the BM2257!I will report on it in September, as I selected the regular courier instead of DHL, so it may take 30 days to arrive and clear customs.Cheers,Jose

author: Furna
author_rank: Frequent Contributor
timestamp: July 18, 2025, 08:26:49 pm
content: Quote from: jebem on July 18, 2025, 07:57:59 pmIt took a little less than 3 weeks to Germany!

author: EEVblog
author_rank: Unknown
timestamp: July 19, 2025, 01:02:38 am
content: Quote from: jebem on July 18, 2025, 07:57:59 pmThe "regular courier" is your local postal service mostly. It gets handed off to whoever is appropriate in each country.DHL Express is direct door-door courier and only takes a few days almost anywhere.

author: jebem
author_rank: Regular Contributor
timestamp: July 19, 2025, 02:50:38 pm
content: Quote from: EEVblog on July 19, 2025, 01:02:38 amDave, Thank you for your reply.Yes, my local postal service tends to delay some shipments, in particular when clearing Customs is required.I assume that the EEVBlog Store is not charging VAT and that the Australian Post Service is not notifying the destination Customs service, right?Thank you for your time and support.

author: EEVblog
author_rank: Unknown
timestamp: July 20, 2025, 12:04:55 am
content: Quote from: jebem on July 19, 2025, 02:50:38 pmCorrect. I ship to 50+ countries, so the burden to register for taxatation in every country (and state in some cases) would be insane.I only collect GST in Australia because I am legally obligated to do that as a local seller.

author: Kleinstein
author_rank: Super Contributor
timestamp: July 20, 2025, 11:53:42 am
content: For shipping to most countries there should be a sticker / information for customs. So customs on the receiving country would get the information and in most countries would collect some import duties or VAT. How that is handled depends on the country.

author: EEVblog
author_rank: Unknown
timestamp: July 21, 2025, 12:17:46 am
content: Quote from: Kleinstein on July 20, 2025, 11:53:42 amIt's electronic these days, it's called Paperless Clearance/Trade

author: jebem
author_rank: Regular Contributor
timestamp: July 29, 2025, 03:43:31 pm
content: Quote from: EEVblog on July 21, 2025, 12:17:46 amI try to not pollute this thread with unnecessary posts like this one.But I thought that would be good to share the trace route for my package, just for fun:July, 21: Travel initiated at NSW, Australia;July, 23: Arrived to Rosebery, Australia;July, 24: Arrived to Frankfurt, Germany;July, 28: Departed from Frankfurt, flight Brussels Airlines SN 2614;July, 28: Arrided to Brussels, Belgium;July, 29: Departed from Brussels to Lisbon, Portugal, flight SN 3815;July, 29: Arrived to Lisbon (not confirmed by the DHL yet, but the flight has landed at 11:09 GMT).EDIT: CTT website is aware now of my package arrival to Lisbon. Good news.So, just 8 days to arrive to the destination. Not bad at all.Now a second (bureaucratic) task will start to get the package out of Portuguese Customs.DHL will have to pass the package to our local CTT post service in charge of the Customs processing.Hopefully CTT will notify me by mail if Sendle included this information in the label.Otherwise I will have to be proactive and check the CTT Customs website using the local reference number that Sendle has assigned to my package once they passed it to DHL back in Australia.

author: EEVblog
author_rank: Unknown
timestamp: July 30, 2025, 12:48:56 am
content: Quote from: jebem on July 29, 2025, 03:43:31 pmUnfortunately that end of destination Final Boss depends on the country, and in some cases, the individual state.

author: HKJ
author_rank: Super Contributor
timestamp: July 30, 2025, 08:13:04 am
content: Quote from: EEVblog on July 30, 2025, 12:48:56 amEU has a system where the seller can prepaid toll, this usual means very fast processing and money saved (for me it is about $30)

author: jebem
author_rank: Regular Contributor
timestamp: July 30, 2025, 12:29:23 pm
content: Quote from: HKJ on July 30, 2025, 08:13:04 amI didn't even wait for customs contact.Yesterday I have inserted a new process into the Portuguese customs website and paid 47 EUR for VAT and handling.Now I can't do anything more on my side.The customs personnel will have to validate my uploaded documents and if all is on order, they will eventually release the package for further handling by the last mile post service.EDIT: Good news! The package was just liberated from Customs and it is being transferred to the CTT local courier. I would expect to have it by Friday.

author: jebem
author_rank: Regular Contributor
timestamp: August 01, 2025, 04:08:36 pm
content: Quote from: jebem on July 30, 2025, 12:29:23 pmMy BM2257 arrived today at 11:30 GMT. The package arrived in one piece and was not smashed.Once again, Thank you Dave, for a smooth transition and excellent support.Just took it apart (partial teardown only) on arrival to inspect for damage during transitThis is an impressive compact full featured DMM available at a moderate cost.The battery cover and the back cover use heavy duty captive screws.Nice to see attention to small details, like having two indents on the battery cover to facilitate its removal using your finger nails.The battery holder contacts use spring loaded terminals on all battery poles, a good solution to maintain good contact under strong vibration.And those 1kV ceramic Fuses! I don't doubt about the CAT category claims on this one.The optional optical BRUA-20X Serial Interface plus Software CD is a tour de force as well.It gives the choice to use the good old 9-pin RS-232 interface or USB.This DMM uses only one-way communication to send data to an external logger device.And those large heavy EMI filtering ferrite beads look a bit excessive, but I am sure they are there for aa good reason. A PC is a very noisy environment.The PCB assemblies look good and clean.The famous properly designed and implemented input circuitry is here in full force.I didn't remove this Input PCB assembly from the Main PCB ass'y at this time, because it requires de-soldering large sized wires that acts as posts to keep the PCB in place, and to install it back it takes a bit of attention to align the four terminal posts to the front cover to allow proper insertion of the test lead jacks, before re-soldering those wires (sorry for my French)It is a pity that no information is allowed to be released by the manufacturer on the custom BTC S26A DMM/MCU/LCD Driver U3 chip.It works on a 4.9152 MHz crystal, a very common value used by several DMM chip manufacturers.There is also a 6-pad MCU interface silkscreened as ICP1, to be used by authorized personnel only.Time to reassemble it.Have inserted the included AAA batteries. The double spring contacts requires some care to have the positive pole properly seated. Easy job.It came to life nicely!Tested briefly on all input selections.Apart from a 20pF parasitic reading on Capacitance selection, the DMM is very stable and it seems to be calibrated enough to agree with some other DMMs I have here with higher resolution and claimed accuracy.Concerning the Capacitance measurements, this DMM is good to read capacitors from 100pF and above. Smaller values are hard to register.A 100pF will register as 120pF, but it will read as 100pF when using the useful REL function to null that parasitic 20pF value.

author: HKJ
author_rank: Super Contributor
timestamp: August 01, 2025, 11:27:13 pm
content: Quote from: jebem on August 01, 2025, 04:08:36 pmTry using TestController on the PC side, it has much better functions than the supplied software.EEVBlog thread:https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/Downloadhttps://lygte-info.dk/project/TestControllerIntro%20UK.htmlat the bottom of the page.

author: BILLPOD
author_rank: Frequent Contributor
timestamp: August 02, 2025, 02:01:46 pm
content: Good Morning Jebem, Thank you for your thorough and detailed analysis of the BM2257, with great photos.Very much appreciated by all, I'm sure. Good job!!!

author: jebem
author_rank: Regular Contributor
timestamp: August 03, 2025, 11:21:00 am
content: Quote from: BILLPOD on August 02, 2025, 02:01:46 pmThank you, you are very kind.Quote from: HKJ on August 01, 2025, 11:27:13 pmYes, I was aware of this good alternative, Thank you!.Here are some random tests to check if my teardown procedure was destructive (Apparently the DM is robust enough to have survived my aggression).BM2257_AC_1 - As usual, I submit any of my new DMMs to a 230VAC (nominal) AC outlet measurement for at least 5 minutes long. Nice yellow backlight!BM2257_AC_2 - Selecting EF detection with the test leads resting at the table would give maximum readings. Amazing. That is what my EMF meter is doing.BM2257_CAP_1 - 20pF parasitic reading.BM2257_CAP_2 - 100pF capacitor registered with REL selected to null the 20pF parasitic value.BM2257_CAP_3 - 4.5uF 5% Motor Start Cap, very good reading, similar to what most of my DMMs and LCRs are doing.BM2257_RES_1 - 1KR 0.1%, perfect.BM2257_RES_2 - 1R 0.1%, it reads 1.0 most of the time, but sometimes it blinks momentarily to 1.1, as seen here (lots of shots to get this one!).BM2257_RES_3 - 10MR 0.1%, within the 2% DMM specification for this range.BM2257_RES_4 - 50MR 5% HV, a reading close to what a ZOYI ZT-DQ02 LCR shows, so again within this DMM specs.