Thoughts about Mastech MS8340B - Page 1
Forum section: electronics / testgear

author: silviustro
author_rank: Contributor
timestamp: December 11, 2017, 07:34:37 pm
content: Hello everyone,Over the past month I've been looking to buying a multimeter in the $50-100 range. My first choice right now is the Uni-T UT61E, I know it isn't that safe, but it has impressive specs for the price. I will mostly use it to measure low current low voltage devices. But I sometimes need to measure mains up to 300V.While browsing for other multimeters today i found the Mastech MS8340B for $105 in europe. It has 22000 counts 0.05%+3 accuracy on the DC range. It is also GS certified CATIII 1000V. Which brings me to the next thing, why haven't i heard of this meter until now? I have tried looking for it on a couple of forums, on youtube and other websites, and nothing, nada, nones. No reviews, no info, no opinions.Here's the manual/datasheet:http://www.automation24.ir/media/uploads/files/products/Mastech_MS8340B_User_%20Manual.pdfSo, what do you guys think about the Mastech MS8340B as a multimeter mainly for electronics use? is Mastech a good brand? Is the MS8340B better than the UT61E?

author: rsjsouza
author_rank: Super Contributor
timestamp: December 11, 2017, 07:46:55 pm
content: In my experience, Mastech does not impose much quality control on their products, and several of their products are quite cheap. I personally find this a very high price for this brand, especially considering that some distributors in Europe carry Brymen products (one example ishere), but that is highly dependent on the accessibility you have to these distributors.

author: silviustro
author_rank: Contributor
timestamp: December 11, 2017, 07:55:35 pm
content: So that's why I haven't heard of this model that much... I would've guessed the GS certification was worth something?You're right about the price. At this price point I can get two UT61E and replace the fuses and PTCs to make it safer.Besides TME, there is no other distribuitor of Brymen products in my country, at least, none I know of. But for some reason I don't like Brymen products that much, they look weird, the displays have a lower count and the PC cable is never included...

author: PA4TIM
author_rank: Super Contributor
timestamp: December 11, 2017, 08:33:27 pm
content: Quote from: silviustro on December 11, 2017, 07:55:35 pmYeah, that are indeed the most important things when it comes to multimeters

author: nicalitz
author_rank: Regular Contributor
timestamp: December 11, 2017, 09:25:00 pm
content: I have two older Mastech meters lying around somewhere. Not really impressed with them at all. The accuracy was way out of spec, even back when I got it. Build quality is not that great. Don't know what their up to these days, but I wouldn't recommend it.On the other hand, I quite like the Uni-T UT61E. We have a few of them at work. I'm rather fond of comms in a DMM. Protocol of these Uni-T meters can be a bit cumbersome, but easy to write a little data logging app once you get the hang of it.If your looking for something low cost, I'd considering the ANENG 8009. Would't necessarily trust it for mains, but for electronics work, its good value for money.

author: silviustro
author_rank: Contributor
timestamp: December 11, 2017, 09:40:09 pm
content: Thanks for your reply. Yes, the Uni-T UT61E is actually the lowest cost DMM i've seen with comms. I've heard about the ANENG 8009, but i'd like something that is also good enough for some mains work.I have been taking a look at the Fluke 17B+ as well, but to my understanding, besides not being True RMS, it's also not that good for electronics work, as it isn't that accurate. In that regard an Amprobe AM-520 would be better.I'm still deciding between the Uni-T UT61E, Amprobe AM-520 and Brymen BM235. The Amprobe has terrible continuity testing and the Brymen is quite expensive and doesn't have the features the UT61E has, on the other hand, it's independently tested.

author: nicalitz
author_rank: Regular Contributor
timestamp: December 11, 2017, 10:08:14 pm
content: The Uni-T and Amprobe are very similar in terms of design and build quality. The BM235 is probably the better option if you're going to be working on mains.It all comes down to what you want to do with it. Personally I'd consider spending $50 on the Uni-T for the comms and electronics work and buying an old second hand Fluke for mains work. I recently picked up an old Fluke 77 for around $40. Does the job. And two meters are better than one.

author: silviustro
author_rank: Contributor
timestamp: December 11, 2017, 10:30:37 pm
content: I'd have to say, that's some solid advice. I was actually thinking about it, maybe buying a Fluke 101 or a second hand older Fluke or Hioki meter.There's also the option of buying the German version of the UT61E which is supposedly independently tested and certified for EN 61010-1, CAT II/III 600 Vhttps://secure.reichelt.com/ro/en/Digital-Multimeters/UT-61E/3/index.html?ACTION=3&LA=446&ARTICLE=97151&GROUPID=4058&artnr=UT+61E&SEARCH=ut61eThere's a $30 difference between the German UT61E and the Chinese UT61E. That means it's pretty much the same price as the BM235.https://www.tme.eu/ro/details/bm235/multimetre-digitale-portabile/brymen/

author: rsjsouza
author_rank: Super Contributor
timestamp: December 11, 2017, 10:37:46 pm
content: Quote from: silviustro on December 11, 2017, 09:40:09 pmIndependent testing goes a long way to give peace of mind with this specification - and yes, it tends to save lives.However, others have postedphotographs of the Uni-T UT139Cand their protection circuitry looks quite interesting - AFAIK although not independently verified.If your budget can withstand the combined prices of the two, I would perhaps get the pair UT61/UT139 provided you take safety precautions when working on mains - and refrain from ever working on the distribution panel.(after I have written the above response...)Quote from: silviustro on December 11, 2017, 10:30:37 pmThat seems to be the most suitable meter for your needs.

author: electricMN
author_rank: Regular Contributor
timestamp: December 11, 2017, 11:13:26 pm
content: If you could stretch your budget just a bit, I'd recommend the Brymen BM257.https://www.tme.eu/en/details/bm257/portable-digital-multimeters/brymen/bm257s/#

author: silviustro
author_rank: Contributor
timestamp: December 11, 2017, 11:57:20 pm
content: Damn, who would've thought choosing a DMM would be so hard. Would the German tested UT61E be suitable for working on a standard house or apartment distribution panel? Seeing how it is CAT II/III 600 V certified.The Brymen BM257 also looks quite nice, but isn't the UT61E more accurate? I'd also need to spend an extra $40 for the comms cable. It does have a backlight, temperature, NCV and it is more robust tho.

author: The Soulman
author_rank: Super Contributor
timestamp: December 12, 2017, 12:36:34 am
content: Specifically for mains work you might wan't to consider something like a Fluke T90:https://secure.reichelt.com/ro/en/Voltage-Testers/FLUKE-T90/3/index.html?ACTION=3&LA=2&ARTICLE=131267&GROUPID=4021&artnr=FLUKE+T90&SEARCH=%252AI've found it's much quicker and easier for 95% of all jobs involving mains for the other 5% you might need specialized equipment anyway.And keep your "electronics" multi meter safely on the workbench.

author: silviustro
author_rank: Contributor
timestamp: December 12, 2017, 01:00:37 am
content: Hmmm... Actually not a bad advice at all. This way I can buy the cheaper Chinese made Uni-T UT61E and a Fluke clamp meter or voltage tester for anything mains related.

author: nicalitz
author_rank: Regular Contributor
timestamp: December 12, 2017, 05:38:17 am
content: Quote from: silviustro on December 11, 2017, 10:30:37 pmInteresting. Haven't heard of these before. Do you know if there are any design or manufacturing differences between the German and Chinese variations? If not, the independent testing should instill some confidence in the safety of the Chinese product.

author: silviustro
author_rank: Contributor
timestamp: December 12, 2017, 06:03:50 am
content: Yes, there are. The GS approved version adds PTCs, MOVs and bigger, better fuses. Other than that, both versions seem to be identical, some users have successfully modded their Chinese version by adding these components.You can take a look here at some pictures below:https://www.eevblog.com/forum/testgear/fuse-for-ut61e/It would be interesting to buy the Chinese version and just mod it. Unfortunately I can't seem to find the PTC and MOV specific model numbers anywhere.

author: nicalitz
author_rank: Regular Contributor
timestamp: December 12, 2017, 06:34:52 am
content: Interesting video on modding the UNI-T UT61E. Probably safer to buy the GS approved version if you really need it.

author: Fungus
author_rank: Super Contributor
timestamp: December 12, 2017, 08:54:53 am
content: Quote from: silviustro on December 11, 2017, 11:57:20 pmEven if you get the "German" UT61E it still doesn't have amazing protection.If you're really going to poke at distribution panels then get a $42 Fluke 101 to go with whatever fancy meter you get for low voltage work. You'll need two meters anyway.Quote from: silviustro on December 11, 2017, 11:57:20 pmHaving a lot of digits doesn't necessarily mean a meter is accurate. eg. A 6000 counts is 0.016% accuracy if all the digits are correct but I don't know many 0.016%-spec handheld meters.6000 counts is six times more accurate than a UT61E even though a UT61E says "22000 counts" on the front.Quote from: silviustro on December 11, 2017, 11:57:20 pmAs noted above, 6000 counts can be plenty accurate.Unless you have a very specific need then I wouldn't obsess over the number of counts. Build quality andconfidenceare much more important in a meter but a UT61E doesn't really deliver either of those.Most of the components and power supplies you'll be using for 'electronics work' are only 5-10% accurate anyway, so...

author: Lightages
author_rank: Unknown
timestamp: December 12, 2017, 04:57:16 pm
content: I would agree that Mastech is to be avoided in general. I also agree that the GS version of the UT61E should be the only one you should consider given your needs. It is also a good idea to have two meters so I would get a Fluke 101 plus the UT61E if you have the budget and insist on having a PC cable. If you have an even higher budget then consider throwing the BM257S into the mix.To be clear, the UT61E GS version is rated CATIII/300V and CATII/600V. CATIII is for use on home power circuits, basically.

author: silviustro
author_rank: Contributor
timestamp: December 12, 2017, 06:01:18 pm
content: Thanks for your explanation guys, some really good advice as well.At this point the discussion would be more about price than anything else, and I think the best thing would be to buy two dedicated meters, one for electronics and another one for electrical work around the house.Chinese UT61E - €50German UT61E - €85Brymen BM257 - €130Amprobe AM530 - €93Fluke 101 - €60Fluke 17B+ - €95Fluke 113 - €100I could get the Chinese UT61E and a Fluke 101 for the price of the Brymen BM257There is also a Chinese Fluke 101 on eBay for about $45, not sure if there are any differences between the Chinese and US versions.The Fluke 17B+ also seems quite appealing, but reading trough the forum people don't seem to recommend it for electronics work, it also lacks True RMS.

author: nicalitz
author_rank: Regular Contributor
timestamp: December 12, 2017, 06:34:24 pm
content: I'd probably go for the Chinese UT61E for electronics work. Lot of functionality and decent accuracy for the price.For a second meter you really have a lot of options. Personally I won't go for the Fluke 101. It just seems a bit overpriced. Would still suggest looking into getting a second hand Fluke, might get a very nice meter for the same price as a new 101.You could also consider the Extech EX330. They're selling for $43 on Amazon at the moment. Build in NCV detector, 4000 count, 600V CATIII UL listed, type-K temperature probe. Good value for money.

author: rsjsouza
author_rank: Super Contributor
timestamp: December 12, 2017, 06:47:00 pm
content: Quote from: silviustro on December 12, 2017, 06:01:18 pmConsidering your budget constraints, I would go for the pair above.IIRC, all Fluke 101 meters are manufactured in China. They also carry a 1 year warranty (not Fluke's lifetime warranty of more advanced models).For the price and specs of the Fluke 17B+, I would instead jump to the Brymen 257.Quote from: nicalitz on December 12, 2017, 06:34:24 pmA word of caution for Extech; in the past they had excellent reputation and features, but several users here saw severe quality control issues - in other words, one could buy a pristine meter while another would buy one with shoddy soldering and screen issues. That severely reduced their popularity around here.

author: nicalitz
author_rank: Regular Contributor
timestamp: December 12, 2017, 07:17:36 pm
content: Interesting. I have limited experience with Extech meters, but they've impressed me thus far. I probably wouldn't avoid the brand. They have quite a reputation, and would likely have addressed the issue as soon as it became public. But its definitely worth keeping in mind. Thanks for the warning.

author: silviustro
author_rank: Contributor
timestamp: December 12, 2017, 07:44:07 pm
content: I took a look at the Extech while I began searching for a meter. I've heard about the Extech EX330 being the best "good" cheap meter out there. Relatively safe for mains, but nothing above that.Problem is, like rsjsouza mentioned, Extech seems to have a lot of quality issues. Uni-T on the other hand makes good quality meters, but the problem seems to be that their designs are not safe enough. So the design itself is the problem, not the quality.I took a look at their new meters, like the UT139 and the UT171. They both seem like they have good input protection and are relatively high quality.Maybe in the future we'll have a high quality equivalent of the UT61?

author: PA4TIM
author_rank: Super Contributor
timestamp: December 12, 2017, 08:19:29 pm
content: Maybe first look this video.Joe Smith has some videos on extech. He has two of the same model and a video about it. I have an Extech AC+DC TRMS clamp meter. I do not use it often but never had problems with it. It is not very accurate but I'm spoiled (my cheapest meter is a Brymen BM869s, my most used meter an Agilent U1253A) , btw, I really like the Brymen, it was spot-on and yesterday I measured bij accident 1300V and it did it without problems. I once had a Voltcraft that died with a bang on 1200V, exploded opamps, dead power rails, even the display controller was fried.The problem with medium cheap meters is that it is always a gamble about quality. They are build with one goal, to be as cheap as possible (in their class). That can be done in 2 ways. Build it with the cheapest parts and cut corners where possible but make it very good looking with lots of features (unit-t) Or build it as a tank with good parts but make it simple with no bell and whistles. Like a fluke 101,https://youtu.be/i2Tkm21dI1g

author: nicalitz
author_rank: Regular Contributor
timestamp: December 12, 2017, 08:23:47 pm
content: I think it has a lot to do with the fact that Uni-Trend is one of the few multimeter manufacturers that cater primarily for the Chinese/Asian market (even though they've become quite popular outside China in the last few years). A lot of the Uni-Trend meters seem well designed (i.e., the layout and component selection seems more 'educated' than their Chinese competitors, such as Mastech), but they are forced to drive costs down to compete. When it comes down it, they would likely prioritise functionality over safety.I would assume that, as long as they serve primarily the Chinese market, their 'working class' meters such as the UT61 will be functionality over safety.

author: Lightages
author_rank: Unknown
timestamp: December 12, 2017, 08:52:36 pm
content: I don't know where you are getting your prices from but tme.eu is selling the BM257S €104 before shipping. I don't know if you are counting shipping for all the prices or not.

author: joeqsmith
author_rank: Super Contributor
timestamp: December 12, 2017, 09:14:59 pm
content: I have not seen this model and believe it's the first Mastech I have seen with some sort of cert. I have ran a few of them and use one for working in the garage and such on low voltage circuits. These have all been fairly low cost and I consider the one I am using disposable. I'm on my second one. The display started going bad in the previous one. If you buy one, I would be interested in seeing what it looks like inside.

author: silviustro
author_rank: Contributor
timestamp: December 12, 2017, 09:19:42 pm
content: Oh Right! Forgot to mention, that was the price with shipping and all the add-ons, like the PC cable, which would put the Brymen BM257S on the same category feature wise as the UT61E

author: silviustro
author_rank: Contributor
timestamp: December 12, 2017, 09:22:27 pm
content: I think someone should buy a Mastech MS8340B and send it to joe to sacrifice it... for science!All jokes aside, it looks like quite a solid meter on paper. That's why I started this thread initially, i was surprised to see no one mention it on the forum.It seems most people dislike Mastech because of their quality control issues, maybe they upped their game with this meter?

author: nicalitz
author_rank: Regular Contributor
timestamp: December 12, 2017, 09:53:24 pm
content: Would be very interested to see a teardown and thorough test. Have seen both GS and ESL certified. They've been around for a long time, wouldn't be all that surprised if they managed to learn from past mistakes. Know how long the MS8340B has been on the market? Can't seem to find much info.

author: joeqsmith
author_rank: Super Contributor
timestamp: December 12, 2017, 10:14:24 pm
content: Quote from: silviustro on December 12, 2017, 09:22:27 pmPossible. Funny as many companies appear, to me anyway, to feel the need to offer cheap low end products in order to compete. If Keysight were selling a cheap meter that the detent spring broke after a few thousand cycles, pretty soon people may start to associate the brand with low quality. But it's Keysight, so that won't happen. Oh wait...

author: rsjsouza
author_rank: Super Contributor
timestamp: December 12, 2017, 10:37:58 pm
content: Regarding the quality control, I have recently purchased a Mastech MAS830L (the evolution to the ubiquitous M830B). It is a fine meter, but it came with a severe quality control flaw: an extra rotary switch contact spring loose inside the housing. It is much better than the M830B models (a.k.a. Harbor Freight), but to me this alone is too dangerous to pass for the common man.Aninteresting threadwhere some regulars share their experiences...

author: silviustro
author_rank: Contributor
timestamp: December 12, 2017, 11:10:51 pm
content: Can't find much info on the MS8340B either (AKA, the reason i started the thread). But it seems it was made available anywhere between January and May of this year.It would be really interesting for someone to buy it and test it out for everyone to see.https://www.aliexpress.com/item/MASTECH-MS8340B-High-Quality-Auto-Range-True-RMS-Digital-Multimeter-DMM-Capacitance-Frequency-Test-USB-Interface/32668190294.htmlI have a distributor here that sells it for $100. If I had a bit more money I'd do it myself