EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: retiredcaps on August 03, 2015, 06:31:37 am
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Saw this new (Aug 2, 2015) set of videos and am downloading now to watch. 9 parts, nearly 1GB of bandwidth at 360p, $767USD spent, 215 minutes worth of DMM testing. :-+
https://www.youtube.com/channel/UCYVMnw_W7-Rq-yJk80vprug/videos (https://www.youtube.com/channel/UCYVMnw_W7-Rq-yJk80vprug/videos)
This person, eevblog member, 5ky, also has done some other DMM reviews in the past.
https://www.eevblog.com/forum/profile/?u=110170 (https://www.eevblog.com/forum/profile/?u=110170)
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6 part video series! :o
Comparing that many meters is not easy though, hats off :-+
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Thanks! It'll be more like 8 or 9 parts--I'm still cutting and uploading, but hats off to you for all of your prior videos like this. It's a LOT more work that I had realized. I assumed I would whip them out of their packaging and knock it out in a day. Boy was I wrong.
I hope to have them all up by tomorrow afternoon (central time, US)
Cheers!
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It's a LOT more work that I had realized. I assumed I would whip them out of their packaging and knock it out in a day. Boy was I wrong.
Sorry, but I can't help but wipe the grin off my face ;D
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Which one does auto-ranging or continuity?
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Which one does auto-ranging or continuity?
I test auto-ranging and continuity in part 8 which is still uploading right now. Should be done in an hour or two. My 5 megabit upload limit is making this take forever :(
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I test auto-ranging and continuity in part 8 which is still uploading right now. Should be done in an hour or two. My 5 megabit upload limit is making this take forever :(
You youngsters and your super fast 5Mbps connections!
When I was a young video blogger...
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just a quick glimpse and i can see 1 very obvious tell tale signs screaming OEM-ed from UNI-T ... those springy split banana sockets ! ... :D
will there be a 1kV basic DCV/ACV input test to see its basic survivability? (not to blow it up no no)
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Wow, that is quite the impressive set of videos. Good job!
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just a quick glimpse and i can see 1 very obvious tell tale signs screaming OEM-ed from UNI-T ... those springy split banana sockets ! ... :D
will there be a 1kV basic DCV/ACV input test to see its basic survivability? (not to blow it up no no)
Yup--but that will be in a couple week. I want to do a full detailed review of each meter before I do things that could potentially kill the meter. (drop test, mains on ohms, 1000v, etc)
Definitely LOTS of meters with striking similarities in kickstands and battery doors. I definitely would not be surprised if Uni-T oem'd half of those meters to be honest.
I'm waiting for the flame war for my overall praise of the Uni-T's. I qualify everything and stand by my choices though. :-)
Once I find the free time, perhaps next week, I'll throw results of the data into a spreadsheet. I bought a domain name too and have a database started--just need to whip up some front end. I have an idea for a web app that asks you "0-Don't Care" through "10-Must Have" of features and capabilities of multimeters, it uses those as weights, and then orders the multimeters in order by the end-user's weighting choices. Could be useful. Could be useless. I might do it either way just for a fun project. Haven't done a web app in a while. But the spreadsheet I'll definitely finish putting data into so that we can get an objective look at which meters of this bunch are better than others.
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You missed the Vichy VC-97 multimeter .. or is it too cheap to participate in the multimeter shoot out :)
Wonder if the R&D department at Vichy is working on some big secret project ... Bluetooth ... Data logging ... 6 1/2 digits =)
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You missed the Vichy VC-97 multimeter .. or is it too cheap to participate in the multimeter shoot out :)
Wonder if the R&D department at Vichy is working on some big secret project ... Bluetooth ... Data logging ... 6 1/2 digits =)
I considered picking one up but already had 15 multimeters to test and Dave had already covered that one :-)
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You missed the Vichy VC-97 multimeter .. or is it too cheap to participate in the multimeter shoot out :)
Wonder if the R&D department at Vichy is working on some big secret project ... Bluetooth ... Data logging ... 6 1/2 digits =)
I have seen those features on a new one from Owon http://www.saelig.com/MFR00062/b35t.htm (http://www.saelig.com/MFR00062/b35t.htm). Right in this price range too.
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Okay, I managed to watch most of the 215 minutes. :popcorn:
Some observations and comments.
A lot of the meters in your shootout are rebranded meters.
CircuitMate DMR6550 - rebranded CEM DT-932N (China)
http://www.cem-instruments.com/en/pro/pro-483.html (http://www.cem-instruments.com/en/pro/pro-483.html)
Klein MM2000 - rebranded Fine 700 Instruments (Korea)
http://www.finest.co.kr/html/pro_02.html (http://www.finest.co.kr/html/pro_02.html)
Southwire 12070T - rebranded CEM DT9962T (China)
http://www.cem-instruments.com/en/pro/pro-481.html (http://www.cem-instruments.com/en/pro/pro-481.html)
http://simvolt.ua/images/detailed/1/9962t_1.jpg (http://simvolt.ua/images/detailed/1/9962t_1.jpg)
BK Precision 2705B - rebranded Chung Instruments
Likely a variation of the CIE-162
http://www.loelectronics.com/en/product/DIGITAL-MULTIMETER/639 (http://www.loelectronics.com/en/product/DIGITAL-MULTIMETER/639)
UEI UTLDM2 - rebranded Mastech (China)
Likely a variation of the Mastech MS8237B.
http://www.p-mastech.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=208&category_id=3&option=com_virtuemart&Itemid=29&vmcchk=1&Itemid=29 (http://www.p-mastech.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=208&category_id=3&option=com_virtuemart&Itemid=29&vmcchk=1&Itemid=29)
Extech 430 - likely a CEM rebrand due to tall exaggerated LCD digits, but I cannot find equivalent on CEM's website.
Tekpower TP40 - rebranded Velleman VA40 (China)
http://mastech.com.cn/html/en/products-va40.htm (http://mastech.com.cn/html/en/products-va40.htm)
Notes:
1) The MOVs in most, but not all, of your multimeters are blue colored which you are mis-identifying as PTCs. For example, here is a picture of the Fluke 107 from
https://www.eevblog.com/forum/testgear/review-first-impression-of-the-fluke-107-multimeter/ (https://www.eevblog.com/forum/testgear/review-first-impression-of-the-fluke-107-multimeter/)
The two blue components circled in blue are MOVs. The green component circled in green is a PTC. The yellow circled component is a 1k ohm fusible resistor.
MOVs may also be silk screened on the pcb as MOV, SG (spark gap). On the Fluke 107, the MOVs are silkscreened RV1 and RV2.
In the Tekpower, the mustard yellow components are the MOVs (3) and the green components are the PTCs (2). I will leave it to you to identify the MOVs when you do the individual meter reviews.
If you are unsure, you can always measure the PTC and MOVs in circuit. A PTC should be around 1k ohm. A MOV will show 0L (out of range/overload) ohm.
Like everything else, there are different varieties of PTCs and MOVs in terms of quality, tolerance, voltage, etc ratings.
2) Extech EX430 - piece of solder inside the multimeter. Many Extech multimeters have soldering problems. I'm not 100% sure who makes the EX430 for them, but my own experience with a EX430 is documented here
https://www.eevblog.com/forum/testgear/extech-ex430-multimeter-teardown-photos/ (https://www.eevblog.com/forum/testgear/extech-ex430-multimeter-teardown-photos/)
https://www.eevblog.com/forum/testgear/extech-ex330-quality-issue/ (https://www.eevblog.com/forum/testgear/extech-ex330-quality-issue/)
https://www.eevblog.com/forum/testgear/teardown-extech-ex570-my-first-but-also-last-extech/ (https://www.eevblog.com/forum/testgear/teardown-extech-ex570-my-first-but-also-last-extech/)
http://mrmodemhead.com/blog/gallery/craftsman-82003/ (http://mrmodemhead.com/blog/gallery/craftsman-82003/)
3) It looks like Bussmann's new color scheme for their fuses is finally making it into all new multimeters made in 2015.
http://www.cooperindustries.com/content/public/en/bussmann/electrical/resources/product_information/fuses-made-simple-control-circuits.html (http://www.cooperindustries.com/content/public/en/bussmann/electrical/resources/product_information/fuses-made-simple-control-circuits.html)
4) Note many tool manufacturers like Klein, Southwire, Craftsman, Snap-On, Mastercraft, Greenlee, Ideal etc do NOT make test equipment. Instead, they rebrand and resell multimeters typically made by others internally unmodified. Even "big name" test and equipment companies like BK Precision, Amprobe and Extech do NOT make their own equipment and simply rebrand and resell like the tool manufacturers.
5) The "baby Fluke" you refer to in your videos is the Fluke 101.
6) Most lower end Extech multimeters are rebranded CEM Instruments meters (same with Southwire). The tall exaggerated slanted LCD digits is a typical sign of the CEM.
http://www.cem-instruments.com/en/pro/sort7-1.html (http://www.cem-instruments.com/en/pro/sort7-1.html)
7) Can you provide clear focused high resolution pictures of each multimeter (both sides of the pcb)?
8] With the insulated bodge wire on the V/ohm jack in the Southwire, it looks to be tucked underneath the 10A current shunt. If the meter is measuring 10A current for a prolonged period of time, how will that insulated bodge wire behave?
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Nice work 5KY. It had good pacing and worth the watch. You gave a pretty good overview of the quality and features.
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Okay, I managed to watch most of the 215 minutes. :popcorn:
Wow, you really know your multimeters! I wish I would've known--I would've picked your brains before buying them all. Could have helped me choose a better set of multimeters to buy. Next time! (perhaps I'll do a $100 shootout in the future if I ever find the time)
I should've paid more attention to the silkscreens for part identification. My bad! It's hard to read the silkscreen with a camera and tripod sitting between me and the multimeter. I think I need to revisit the teardowns. When I get around to that, I'll be sure to break out the DSLR and light tent to get some nice shots of the PCBs for you. Thanks for all the info. You're like a walking multimeter bible!
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Oh, before I forget! I already uploaded the video, but if you haven't seen it, I hooked up a set of gold plated probemaster probes to the Uni-T UT61E and it ended up having a BLAZING fast continuity tester. The crappy stock probes were making it seem like it had a sub-par continuity tester but it was actually the probes holding the meter back. I was really surprised. It makes me wonder how many multimeters out there appear to have bad continuity testers but really have great ones that are being held back by crappy probes.
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The crappy stock probes were making it seem like it had a sub-par continuity tester but it was actually the probes holding the meter back
Known problem with the probes that come with the UT61E. I think it is discussed in the big mega UT61E thread, but since I don't have one, I don't have it bookmarked. I believe cleaning the probes with IPA might help. You should try it and make another video! ;)
https://www.eevblog.com/forum/testgear/just-got-my-new-uni-t-ut61e-and-i-think-it-has-a-problem/ (https://www.eevblog.com/forum/testgear/just-got-my-new-uni-t-ut61e-and-i-think-it-has-a-problem/)
BTW, Dave did a review of the Probe Master probes in eevblog 606 at 23:25. They look really sharp. One set of my really sharp Pomona probes drew blood. Ever since then, I put the plastic guards on the tips and put them away.
http://www.eevblog.com/2014/04/22/eevblog-606-mailbag/ (http://www.eevblog.com/2014/04/22/eevblog-606-mailbag/)
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Could have helped me choose a better set of multimeters to buy. Next time! (perhaps I'll do a $100 shootout in the future if I ever find the time)
In the $100 category, you have a number of choices for a good variety. If you are going to do one, PM me and I can make a suggested list.
I try to keep track of where the multimeters are made with respect to country. Since they are made in different countries, they will likely to be completely different and not simple rebrands.
The companies that actually make multimeters (off the top of my head) are Fluke, Agilent, Yokogawa, Hioki, Mastech, Uni-Trend, Brymen, CEM Instruments, Fine Instruments, Colluck, Appa Technology, Der EE, Sanwa, Gossen, Vichy.
I should've paid more attention to the silkscreens for part identification. My bad! It's hard to read the silkscreen with a camera and tripod sitting between me and the multimeter.
No problem. I have never done a video, but I know enough from Dave and Martin's multimeter videos, it is hard to talk, think, focus, shoot, test, etc in one take. Mistakes, oversights, etc are bound to happen.
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I was curious about the Hioki DT4211 (https://www.hioki.com/products/dmm_insulation_clamp/dmm/1421), which appears to be a rebadged DEREE DE-243 (http://www.deree.com.tw/de-240-3.html) according to this thread (https://www.eevblog.com/forum/testgear/hioki-42114212-quality/). Around $83us on ebay.
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I guess a good lesson learned here is that when performing 'shoot-outs' between DMMs you testing the complete 'system' (meter + leads) not that would help a newcomer to make his choice. I would guess that the meter leads supplied would need it's own shoot-out to allow a buyer to make that a top/high priority to his/her buy/not buy decision.
I know I'm thinking of picking up a set of those master probe leads, got a watch on ebay for a set. Best tip I got from watching the whole 9 videos. :clap:
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Good job :clap:, at the very least we get HD resolution teardowns of many DMMs in great quality all side by side. :-+
Video 7 is the best, all teardowns side by side.
Technical commentary has a lot of debatable points, but aside, the clarity of your videos and that you manipulate them in so many ways makes up for it as viewers can see issues for themselves. Some of those DMMs are very poorly designed for mains use.
Not in your 'shoot out' but worth a look on your channel is the Amprobe PM51A and the Voltcraft VC890.
A fantastic end would be to impulse some of them as Joe Q Smith did and see how they fair.
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/360/ (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/360/)
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Not in your 'shoot out' but worth a look on your channel is the Amprobe PM51A and the Voltcraft VC890.
The Amprobe PM51A is a rebadged Brymen BM22.
http://www.brymen.com/product-html/cata20/Bm20L2.htm (http://www.brymen.com/product-html/cata20/Bm20L2.htm)
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Thanks retiredcaps. I think it safe to say most HHDMMs brands are OEM of others, and only top brands design and build DMM for themselves, or most likely contract ODM for all or parts of it.
Even Fluke is not immune.
https://www.stratos.com/project/fluke (https://www.stratos.com/project/fluke)
The Voltcraft VC890, as 5ky mentions, is a Uni-T, it appears as a modified 171C.
(http://www.conrad.com/medias/global/ce/1000_1999/1200/1240/1246/124600_BB_03_FB.EPS_400.jpg)(http://i01.i.aliimg.com/wsphoto/v0/32229282801/UNI-T-UT171C-Bandwidth-100KHz-Industrial-True-RMS-Digital-Multimeter-Meter-Tester.jpg)
https://www.eevblog.com/forum/testgear/uni-t-ut171a-pictures-and-first-impressions/15/ (https://www.eevblog.com/forum/testgear/uni-t-ut171a-pictures-and-first-impressions/15/)
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A fantastic end would be to impulse some of them as Joe Q Smith did and see how they fair.
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/360/ (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/360/)
If you want to run any of them across the jig, just let me know. Keep in mind that the only meter that I have seen survive at the last setting is the Fluke 101.
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Thanks retiredcaps. I think it safe to say most HHDMMs brands are OEM of others, and only top brands design and build DMM for themselves, or most likely contract ODM for all or parts of it.
Even Fluke is not immune.
https://www.stratos.com/project/fluke (https://www.stratos.com/project/fluke)
CEO of Stratos was ex Fluke employee. A quick link search on linked shows other Stratos employees as ex Fluke.
Mike Nelson
https://www.linkedin.com/pub/mike-nelson/a/870/5a7 (https://www.linkedin.com/pub/mike-nelson/a/870/5a7)
Mark Freeman
https://www.linkedin.com/pub/mark-freeman/19/198/b98 (https://www.linkedin.com/pub/mark-freeman/19/198/b98)
Mark Hastings
https://www.linkedin.com/pub/mark-hastings/a/568/ba7 (https://www.linkedin.com/pub/mark-hastings/a/568/ba7)
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A fantastic end would be to impulse some of them as Joe Q Smith did and see how they fair.
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/360/ (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/360/)
If you want to run any of them across the jig, just let me know. Keep in mind that the only meter that I have seen survive at the last setting is the Fluke 101.
I'd be willing to donate these to your cause:
Uni-T UT61D
Innova 3320
Tekpower TP40
Circuit-Test DMR-6550
Holdpeak HP-760H
If you haven't tested any or all of those, let me know and I'll happily mail them to you for some cheap multimeter carnage. :-+
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A fantastic end would be to impulse some of them as Joe Q Smith did and see how they fair.
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/360/ (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/360/)
If you want to run any of them across the jig, just let me know. Keep in mind that the only meter that I have seen survive at the last setting is the Fluke 101.
I'd be willing to donate these to your cause:
Uni-T UT61D
Innova 3320
Tekpower TP40
Circuit-Test DMR-6550
Holdpeak HP-760H
If you haven't tested any or all of those, let me know and I'll happily mail them to you for some cheap multimeter carnage. :-+
Sounds good. These are all different from what I tested. When you are done with them, shoot me a PM and I'll send you my contact information. Saw you ran the Fluke 107. I actually thought about buying that meter to see if it would hold up. If you have no plans for it after you have finished, I would be interested in it.
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Good find. That can help get contracts. To use Fluke's name for promotion, seems to me they remain in good terms with them. That piqued my interest.
http://www.bloomberg.com/research/stocks/private/snapshot.asp?privcapId=1502267 (http://www.bloomberg.com/research/stocks/private/snapshot.asp?privcapId=1502267)
Look at their project CV:
https://www.stratos.com/all-projects (https://www.stratos.com/all-projects)
Involved managers do mention their connections to Fluke, just click on their names for more.
https://www.stratos.com/about/management (https://www.stratos.com/about/management)
http://www.glassdoor.com/Reviews/Stratos-Product-Development-Reviews-E327530.htm (http://www.glassdoor.com/Reviews/Stratos-Product-Development-Reviews-E327530.htm)
Based on their corporate address, they are ~ 1 hour from Fluke's main office in Everett, WA.
https://www.google.com/maps/dir/6920+Seaway+Blvd,+Everett,+WA+98203/2401+Elliott+Ave,+Seattle,+WA+98121/@47.7193538,-122.6890633,9z/data= (https://www.google.com/maps/dir/6920+Seaway+Blvd,+Everett,+WA+98203/2401+Elliott+Ave,+Seattle,+WA+98121/@47.7193538,-122.6890633,9z/data=)!4m14!4m13!1m5!1m1!1s0x5490010f0ab1d28b:0xcd1d59d2048424aa!2m2!1d-122.2650571!2d47.9344994!1m5!1m1!1s0x549015520e162309:0xaa10d8172120ae6c!2m2!1d-122.350113!2d47.612817!3e0
CEO of Stratos was ex Fluke employee. A quick link search on linked shows other Stratos employees as ex Fluke.
https://www.linkedin.com/pub/mark-hastings/a/568/ba7 (https://www.linkedin.com/pub/mark-hastings/a/568/ba7)
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A fantastic end would be to impulse some of them as Joe Q Smith did and see how they fair.
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/360/ (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/360/)
If you want to run any of them across the jig, just let me know. Keep in mind that the only meter that I have seen survive at the last setting is the Fluke 101.
I'd be willing to donate these to your cause:
Uni-T UT61D
Innova 3320
Tekpower TP40
Circuit-Test DMR-6550
Holdpeak HP-760H
If you haven't tested any or all of those, let me know and I'll happily mail them to you for some cheap multimeter carnage. :-+
:clap:
I can't wait to see the carnage. :-+
:popcorn:
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Even Fluke is not immune.
https://www.stratos.com/project/fluke (https://www.stratos.com/project/fluke)
SOunds like they were contracted to do the industrial design for it. I doubt they did the whole meter.
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This is a great series of videos :-+
I am amazed at how high quality some of these low cost meters are. And now I know which ones to avoid.
Thanks!
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Just finished watching them all. Great job and fantastic service to the community. Thanks for doing it.
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Thanks to 5ky and joeqsmith :clap:, I hope you folks come to an agreement so we can see how these meters fare as to their CAT ratings, at least on the impulse test. It'll help give reader's insight into their safety.
Ontario, Canada has an interesting experience with DMM accidents. Anyone interested can check the ESA website for details. Here is the summary:
http://www.esasafe.com/ (http://www.esasafe.com/)
http://iaeimagazine.org/magazine/2008/07/16/multimeter-accident-prevention-plan-an-electrical-inspectors-survival-guide/ (http://iaeimagazine.org/magazine/2008/07/16/multimeter-accident-prevention-plan-an-electrical-inspectors-survival-guide/)
The key issue with the Ontario experience is data before and after DMM related safety issues were instituted.
http://www.esasafe.com/assets/files/esasafe/pdf/Multimeter_Brochure.pdf (http://www.esasafe.com/assets/files/esasafe/pdf/Multimeter_Brochure.pdf)
I'd be willing to donate these to your cause:
Uni-T UT61D
Innova 3320
Tekpower TP40
Circuit-Test DMR-6550
Holdpeak HP-760H
If you haven't tested any or all of those, let me know and I'll happily mail them to you for some cheap multimeter carnage. :-+
Sounds good. These are all different from what I tested. When you
are done with them, shoot me a PM and I'll send you my contact
information. Saw you ran the Fluke 107. I actually thought about
buying that meter to see if it would hold up. If you have no plans for
it after you have finished, I would be interested in it.
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He still has the drop tests and AC line voltage tests he was going to run on them.
It would be interesting if any of them fail the AC line voltage to have a look at what failed.
It appears he confuses MOVs for PTCs. The AMPROBE he tested is very similar to the 510 I looked at. Mines been modified but notice that additional MOV.
https://www.youtube.com/watch?feature=player_detailpage&v=PzsQCr9FiFs#t=1712 (https://www.youtube.com/watch?feature=player_detailpage&v=PzsQCr9FiFs#t=1712)
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It appears he confuses MOVs for PTCs. The AMPROBE he tested is very similar to the 510 I looked at. Mines been modified but notice that additional MOV.
Yeah someone else pointed that out as well. I've only ever seen the disc type varisters so it's apparent that I need to start looking at the silkscreen. (which is hard to do with a camera/tripod between you and the DMM)
I'll get a good look through each of these when I get around to the individual reviews of these guys, and I'll get the DSLR out to snap some shots of both sides of the PCBs for each one.
Then after the individual reviews, I'll test each meter doing the mains on ohms test, as well as a 1m drop test. Then I'll send some of them over to Mr. joeqsmith for some serious abuse :-+
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Thanks so much for your work.
Looking forward to videos, take due care as worse case it will be like a dead short inside the meter from mains power.
The Canadian links was mostly DMM accidents, based on the voltage involved its commercial and home wiring issues not the industrial type arc blasts we read about in the OSHA reports. It far less now in Ontario now because of strict rules and CSA rated meters.
A wise user can work with anything knowing and recalling a devices limits, e.g. use a Centech freebie only for CAT 1. But if user forgets just once or someone in your household uses it by mistake in the wrong conditions, it could be a eye opener. Why settle for less when better options exist?
It appears he confuses MOVs for PTCs. The AMPROBE he tested is very similar to the 510 I looked at. Mines been modified but notice that additional MOV.
... I'll test each meter doing the mains on ohms test, as well as a 1m drop test. Then I'll send some of them over to Mr. joeqsmith for some serious abuse :-+
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Yes, I'd be interested, several of those DMMs warn users not to do this, not to use ohms when set for voltage; IEC criteria for a safety rated meter require it to tolerate the maximum rated voltage in any function. Hopefully 5Ky will take his usual good videos of failed PCBs.
He could also ship the dead meters to you for a post mortem check ;) If a microscope were needed I saw you have one that you used on the 87V failure [ BTW those were signal diodes you replace on the 87V? BV199? It appears ruptured within the packaging without arcing] that seems to be easy to take photos with in case you were interested into looking at blown chips in detail.
He still has the drop tests and AC line voltage tests he was going to run on them.
It would be interesting if any of them fail the AC line voltage to have a look at what failed.
It appears he confuses MOVs for PTCs. The AMPROBE he tested is very similar to the 510 I looked at. Mines been modified but notice that additional MOV.
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He still has the drop tests and AC line voltage tests he was going to run on them.
It would be interesting if any of them fail the AC line voltage to have a look at what failed.
It appears he confuses MOVs for PTCs. The AMPROBE he tested is very similar to the 510 I looked at. Mines been modified but notice that additional MOV.
https://www.youtube.com/watch?feature=player_detailpage&v=PzsQCr9FiFs#t=1712 (https://www.youtube.com/watch?feature=player_detailpage&v=PzsQCr9FiFs#t=1712)
just curious, since you have some HV equipment setup ...
i am very interested to know if the test leads provided can actually withstand 1kV ... or more ? especially for the sake of recording some numbers ... maybe the 2.5kV insulation test?
its just a itching curiosity ...
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He still has the drop tests and AC line voltage tests he was going to run on them.
It would be interesting if any of them fail the AC line voltage to have a look at what failed.
It appears he confuses MOVs for PTCs. The AMPROBE he tested is very similar to the 510 I looked at. Mines been modified but notice that additional MOV.
https://www.youtube.com/watch?feature=player_detailpage&v=PzsQCr9FiFs#t=1712 (https://www.youtube.com/watch?feature=player_detailpage&v=PzsQCr9FiFs#t=1712)
just curious, since you have some HV equipment setup ...
i am very interested to know if the test leads provided can actually withstand 1kV ... or more ? especially for the sake of recording some numbers ... maybe the 2.5kV insulation test?
its just a itching curiosity ...
In one of Joe's vids he does lead tests, twisted together but no failures IIRC and much higher than 2.5 KV.
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i am very interested to know if the test leads provided can actually withstand 1kV ... or more ? especially for the sake of recording some numbers ... maybe the 2.5kV insulation test?
There is not much need to do hipot/IR tests of insulated wire at 1kV. These tests are mostly to ensure no major failures like metal chips or broken strands creating a near short exist.
A .050 airgap (in >70% RH) will be a "perfect" insulator to ~2kV. Any sort of insulator can only be better. I have seen medium-quality 300V-rated hookup wire withstand 5kV repeatedly.
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Great videos! I agree too much is said about high voltage stuff when just doing bench work.
:clap: :clap: :clap: :clap: :clap: :clap: :clap:
PS - this thread should probably be pined up top for a while - until someone de-thrones you.
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Please explain to me how this is an alternative.
TBH, im not really sure :-//, maybe a really really lousy DMM dont even have over 10M input impedance in the important selections, so w/o even using a HV test, 1 could judge using this "character"? :-// (ie: XYZ brand, CAT3 rated, but DCV input only has 1Mohm?)
I don't think you will find it's that simple.
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I agree the kV tests seem overkill, but its part of IEC protocols. Beyond insulation its also used for shock hazard for exposed parts of the design that may contact user fingers, it may also be done after the probe has been abused physically and environmentally. For a 1kV rated probe, the steady state test voltage is ~ 10kVdc or 7kVac rms and 13kV impulse and if it says 10A, it can take 10A continuously for? > 2-3 hours without changing any of its rated specs.
Here is a link to a free full IEC DMM test, and the separate test of its probes. I don't know how long this link will be valid. The IEC document itself runs over $100 but pdf shows every step, sans detailed explanation.
http://www.topelcom.gr/cms/M300_3.pdf (http://www.topelcom.gr/cms/M300_3.pdf)
Now, whether the testers are honest about each step of the process is another thing, that's why the CE mark is weak relative to 3rd party marks, like UL. What looks like the M300 Hyelec is in the cover of this safety document from the EU, but maybe its not the same DMM?
Here is a link to a 3rd party test done to a Uni-T probe, it also lists a number of 'brands' its sold under.
http://www.element14.com/community/servlet/JiveServlet/download/42359-3-102013/110103600214-216-217_test%20report.pdf (http://www.element14.com/community/servlet/JiveServlet/download/42359-3-102013/110103600214-216-217_test%20report.pdf)
If the above fails, here is the main link:
http://www.element14.com/community/docs/DOC-42359/l/software-for-tenma-72-9280-for-windows7 (http://www.element14.com/community/docs/DOC-42359/l/software-for-tenma-72-9280-for-windows7)
IMHO the Uni-T test are excellent. Those probes sell as low as $2-3/pair and US eBay about $8/pair delivered. To summarize, you can get quality safe probes for very little money, and its been tested.
Otherwise you may get stuck with these:
http://www.saferproducts.gov/ViewIncident/1417431 (http://www.saferproducts.gov/ViewIncident/1417431)
It doesn't happen to all the Centech probes, but you never know when or if it will fail, and they appear to not have been abused at the time it failed.
i am very interested to know if the test leads provided can actually withstand 1kV ... or more ? especially for the sake of recording some numbers ... maybe the 2.5kV insulation test?
There is not much need to do hipot/IR tests of insulated wire at 1kV. These tests are mostly to ensure no major failures like metal chips or broken strands creating a near short exist.
A .050 airgap (in >70% RH) will be a "perfect" insulator to ~2kV. Any sort of insulator can only be better. I have seen medium-quality 300V-rated hookup wire withstand 5kV repeatedly.
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A reason to discuss "high voltage" rated DMM is that its harder to make them that way, and all certification tests are usually done to insure at least mains voltage level safety. So, even if you rarely use it for mains it has to be built better overall than one that isn't, so the high voltage tests are a mark of better quality design and manufacture at the least.
For example, most bench meters, like the Keysight 34465a are just CAT II or less but they are certified to be CAT II.
DMMs with certifications can still malfunction [ say from a production batch defect] buts the initial tests are so stringent its very unlikely to be unsafe even with the defect. The certifying body also checks the factory to insure production is consistent to give owner's a certified product.
Better manufacturers aspire to higher standards [ usually "6 sigma" or under 3 defects per billion ] which means in production runs of 100,000 or so, defects in products to end users are ~ non-existent, otherwise you end up with this:
http://www.saferproducts.gov/ViewIncident/1197325 (http://www.saferproducts.gov/ViewIncident/1197325)
In which case, the brand name starts to matter above the safety certification. Naturally, you end up paying up front for all those extra quality controls associated with the brand.
Great videos! I agree too much is said about high voltage stuff when just doing bench work.
:clap: :clap: :clap: :clap: :clap: :clap: :clap:
PS - this thread should probably be pined up top for a while - until someone de-thrones you.
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Yes, the certification is only for that one model, so be sure that's the model you buy, and that the company doesn't cheat or there is counterfeit, sell a look-a-alike model that isn't tested.
I'm glad you enjoy the documents, there is lots to see, the details let readers know what the certification really means particularly comparing "CE" vs an NRTL lab like Intertek. I think some other manufacturers will make this data public, at least Amprobe has many on record for its products you can download while Fluke brands do not.
FWIW Amprobe has many rebadged Brymen and Uni-T models, Uni-T has many non-tested models; but if you buy the Amprobe versions of the Uni-T models they are built better with reasonable cost.
the intertek test chart is great information ! :-+
but i think not all UNI-T cables are 1 part number, i think they have many types and as far as i know, my UNI-T probes dont look like they have that much copper in them like in the picture :P, and it definately fails the 13.2a (3.5mm exposed) clause :P. sometimes, i think the companies market a IEC tested part, but sells a different lower grade part. as end users, if the sold item is made 10% inferior, chances are 99.999% they can still get away with it.
i read with amusement in the M300 test report, the equipment they used in the tests. it seems there are quite a number of good graded china test equipment there. there is even 3pc of calibrated HAMMER ! :P (part no CESS065 -067), anyway it must be fun working in such a facility !
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FWIW Amprobe has many rebadged Brymen and Uni-T models, Uni-T has many non-tested models; but if you buy the Amprobe versions of the Uni-T models they are built better with reasonable cost.
Which Amprobe models are from Uni-T?
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To me it appears that the AM-5X0 series are from Uni-T.
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Thanks retiredcaps. I think it safe to say most HHDMMs brands are OEM of others, and only top brands design and build DMM for themselves, or most likely contract ODM for all or parts of it.
Even Fluke is not immune.
https://www.stratos.com/project/fluke (https://www.stratos.com/project/fluke)
The Voltcraft VC890, as 5ky mentions, is a Uni-T, it appears as a modified 171C.
(http://www.conrad.com/medias/global/ce/1000_1999/1200/1240/1246/124600_BB_03_FB.EPS_400.jpg)(http://i01.i.aliimg.com/wsphoto/v0/32229282801/UNI-T-UT171C-Bandwidth-100KHz-Industrial-True-RMS-Digital-Multimeter-Meter-Tester.jpg)
https://www.eevblog.com/forum/testgear/uni-t-ut171a-pictures-and-first-impressions/15/ (https://www.eevblog.com/forum/testgear/uni-t-ut171a-pictures-and-first-impressions/15/)
It appears in that case Fluke hired a design firm to do the industrial design. I'm sure Fluke still engineered the guts. Apple did this (may still do it) all the time using companies like Function Engineering, Frog and IDEO to help with product design. It's really a bit of a spectrum. At one end you have companies that are doing almost every thing in house. Ford and the River Rouge Plant was perhaps the most extreme case (iron ore goes in, cars go out). At the other end we have companies that are clearly sticking their names on other products with very little to no design input (likely most of the small players who sell rebadged UNI-T and CEM models). Then we have that large range in the middle where a company is heavily involved but doesn't do all the work. It is very common for a company with technical expertise to hire a design firm to handle industrial design aspects as we are seeing with the Fluke 170 series. You will also see this with cars such as BMW giving design inputs to a ZF, GM, or Aisin transmission they wish to use in one of their cars. Perhaps the distinction is BMW, and likely Fluke still had their engineering and management coordinating the whole show even if others did some of the work. Greenlee on the other hand almost certainly submits a wishlist (specs) to Brymen and let's Brymen handle all the design work.
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Lightages is right, but here's a whole list.
http://www.amprobe.com/amprobe/usen/service/certifications/default.htm?resource=certifications (http://www.amprobe.com/amprobe/usen/service/certifications/default.htm?resource=certifications)
(https://www.eevblog.com/forum/testgear/new-$50-multimeter-shootout-15-dmms-compared/?action=dlattach;attach=165359;image)
FWIW Amprobe has many rebadged Brymen and Uni-T models, Uni-T has many non-tested models; but if you buy the Amprobe versions of the Uni-T models they are built better with reasonable cost.
Which Amprobe models are from Uni-T?
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@saturation, Thanks for that photocopy/fax paper shot. From teardowns on the AM-5X0, people have observed that there are similarities between the Uni-T meters, but there was never any hard proof that Uni-T made them. For example, companies that resell CEM meters under their own brand only change the exterior colors, but the internal pcb is labelled with CEM's part number.
This photocopy/fax may have been in another thread somewhere, but this is the first time I recall seeing it.
edit: fixed typo.
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You're welcome. I don't know if Amprobe has released such detail before because their website is redesigned. The main link I left to their certification page provides pdfs, some have lots of detail. I checked some of the Brymen look-a-like DMMs but they managed to remove the manufacturer from it, it only says Amprobe, but not this Uni-T series, maybe it slipped by?
@saturation, Thanks for that photocopy/fax paper shot. From teardowns on the AM-5X0, people have observed that their are similarities between the Uni-T meters, but there was never any hard proof that Uni-T made them. For example, companies that resell CEM meters under their own brand only change the exterior colors, but the internal pcb is labelled with CEM's part number.
This photocopy/fax may have been in another thread somewhere, but this is the first time I recall seeing it.
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Hey retiredcaps--do you know if anyone has rebranded the Finest 707? It looks like it's a pretty nice 50,000 count DMM, but I can't seem to find anywhere that I can buy it online. If the quality is anything like that Klein mm2000 (that you said is a rebranded finest), I'd imagine it could potentially be a pretty nice DMM.
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Hey retiredcaps--do you know if anyone has rebranded the Finest 707?
Finest 707 = UEI DM397.
Already video reviewed by three eevblog members.
https://www.youtube.com/watch?v=3uUIMjh1Pj4 (https://www.youtube.com/watch?v=3uUIMjh1Pj4)
https://www.youtube.com/watch?v=53wZU4yOr1k (https://www.youtube.com/watch?v=53wZU4yOr1k)
https://www.youtube.com/watch?v=x03LoSByf1E (https://www.youtube.com/watch?v=x03LoSByf1E)
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Hey retiredcaps--do you know if anyone has rebranded the Finest 707?
Finest 707 = UEI DM397.
Already video reviewed by three eevblog members.
Excellent--I had a feeling you'd know :-+ Thank you sir. Much appreciated!
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DM397, very nice (if only it works accurately?). DMM with micro ohm capability and is portable. and cheaper than brymen (TE depot on sale USD226, maybe they have problems with the entire batch? )
the inside looks somewhat flimsy ... from which country is this DM397 made in? doesnt look like china?
Korea
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Excellent video on
"$50 Multimeter Shootout Update (Continuity Test w/ Quality Probes) - #0079 ".
You might be the first person who demonstrated that changing to the quality probe from the cheap stock probe would make so difference on multimeter's Test!
Nice! :)
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Yeah, it was cool to see the difference demonstrated.
Here's the link to the vid for your convenience:
https://www.youtube.com/watch?v=GHN_9l8kVNo (https://www.youtube.com/watch?v=GHN_9l8kVNo)
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https://www.youtube.com/watch?feature=player_detailpage&v=fihUrdsyddc#t=117 (https://www.youtube.com/watch?feature=player_detailpage&v=fihUrdsyddc#t=117)
Just to be clear, the 101 is what survived. I have never tested the 107, however I did run the 87V which was also damaged. The 101 I have is VERY robust. The generator ended up around 20J at 13KV. It's not can crushing energy but could be lethal. I started well under a J and still had meters fail.
Good job with your continued efforts making these videos. Looking forward to seeing the AC line voltage tests.
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https://www.youtube.com/watch?feature=player_detailpage&v=fihUrdsyddc#t=117 (https://www.youtube.com/watch?feature=player_detailpage&v=fihUrdsyddc#t=117)
Just to be clear, the 101 is what survived. I have never tested the 107, however I did run the 87V which was also damaged. The 101 I have is VERY robust. The generator ended up around 20J at 13KV. It's not can crushing energy but could be lethal. I started well under a J and still had meters fail.
Good job with your continued efforts making these videos. Looking forward to seeing the AC line voltage tests.
Good point. I didn't consider the fact that the 107's additional functionality could introduce weaknesses. It's great to hear that the Flukes are still as reliable as they're known to be. I'm curious how the 17B would fair
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I am not sure where the Fluke 87V I tested would have failed, only that it did not handle the same transient that the 101 did. I would like to run your 107 across it. Before I do anything, I would like to make a test jig that I can easily set the waveform. As it is now, all I could tell you is if your meters could survive what the 101 was hit with. The generator evolved as the meters fell by the wayside.
I am also interested in how the Brymen holds up to some of this. Looks like the front end on that meter may be alright but until I hit it, hard to say.
Looking forward to your next review.
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I am not sure where the Fluke 87V I tested would have failed, only that it did not handle the same transient that the 101 did. I would like to run your 107 across it. Before I do anything, I would like to make a test jig that I can easily set the waveform. As it is now, all I could tell you is if your meters could survive what the 101 was hit with. The generator evolved as the meters fell by the wayside.
I am also interested in how the Brymen holds up to some of this. Looks like the front end on that meter may be alright but until I hit it, hard to say.
Looking forward to your next review.
The equipment / tool hoarder in me doesn't want to let go of the nicer multimeters, but the child inside of me wants to see some multimeter destruction. How about I mail you all fifteen multimeters and you mail back the ones that survive? (which I'd imagine will only be the 107?)
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:-DD :-DD
Well, I think I can satisfy your desire to see some meter carnage that but to be honest, I don't think I could pull the trigger on that VC890 OLED meter of yours. It just looks way too nice.
It will take me some time to sort out the generator. To be clear, I would still not be trying to blow the backs off the meters. Rather, just something to make this an easier job and provide us with a better idea how they stack up with each other. If you are concerned at all about the AC line test, I would be willing to add this in the mix as well.
I would also like to do a post analysis of the meters that fail and possibly repair them. This will all take a fair amount of time.
So take your time with your reviews and I will start working on a better way to test them.
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I will do my part by waiting eagerly to watch/read the results ;D
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:-DD :-DD
Well, I think I can satisfy your desire to see some meter carnage that but to be honest, I don't think I could pull the trigger on that VC890 OLED meter of yours. It just looks way too nice.
It will take me some time to sort out the generator. To be clear, I would still not be trying to blow the backs off the meters. Rather, just something to make this an easier job and provide us with a better idea how they stack up with each other. If you are concerned at all about the AC line test, I would be willing to add this in the mix as well.
I would also like to do a post analysis of the meters that fail and possibly repair them. This will all take a fair amount of time.
So take your time with your reviews and I will start working on a better way to test them.
No worries--I'll probably be done with the $50 ones by next weekend. Then I'll send them your way! I'm excited to see how they each do. :popcorn:
And I wasn't intending on sending the VC890--that multimeter I rather like. It's not as fancy as my 87V or U1253B, but man, that screen shows up great on video. (and outlasts the Agilent's battery by a huge order of magnitude)
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i just saw this video, on the VC DMM
https://www.youtube.com/watch?v=DT2MU32la2c (https://www.youtube.com/watch?v=DT2MU32la2c)
@ 40+ min mark, it somehow beat the LCR meter in reading the 4700uF cap ( a agilent LCR? beaten?), imo german engineering/design are really scary in a good way >:D
and there is currently NO CLONE of this in china market. which means likely final assembly is in germany?
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Oh, before I forget! I already uploaded the video, but if you haven't seen it, I hooked up a set of gold plated probemaster probes to the Uni-T UT61E and it ended up having a BLAZING fast continuity tester. The crappy stock probes were making it seem like it had a sub-par continuity tester but it was actually the probes holding the meter back. I was really surprised. It makes me wonder how many multimeters out there appear to have bad continuity testers but really have great ones that are being held back by crappy probes.
I have seen the same but the other way around. My Brymen 869s is really fast as a continuity tester with the standard probes but when using a Fluke test lead set it became slower and very scratchy, even after cleaning the tips.
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No worries--I'll probably be done with the $50 ones by next weekend. Then I'll send them your way! I'm excited to see how they each do. :popcorn:
And I wasn't intending on sending the VC890--that multimeter I rather like. It's not as fancy as my 87V or U1253B, but man, that screen shows up great on video. (and outlasts the Agilent's battery by a huge order of magnitude)
Looking forward to it.
Maybe 15 years ago I would have thought of the 87V as a fancy meter. It's dated, doesn't have many features but gets the job done in most cases. The VC890 is loaded and it looks great!
Watched your latest BK review. :-+ I thought you were just a bit reserved after seeing possibly the worse continuity tester in the history of mankind. :-DD Half a second just to detect??? Did that decision come from marketing or sales?
I have seen the same but the other way around. My Brymen 869s is really fast as a continuity tester with the standard probes but when using a Fluke test lead set it became slower and very scratchy, even after cleaning the tips.
I may toss the Brymen in the mix with the rest of 5KY's meters.
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can i ask to measure the input impedance of the VC890 on each selector range w/o power on? and compare that to the fluke 101 / 87 and 1253B ?
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can i ask to measure the input impedance of the VC890 on each selector range w/o power on? and compare that to the fluke 101 / 87 and 1253B ?
sure--I'll post results once I'm home from work
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That Voltcraft VC890 is a pile of shit dressed to thrill, it's basic dc accuracy is +-0.8%, that's crap and it's boasts 60000 count :palm:
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can i ask to measure the input impedance of the VC890 on each selector range w/o power on? and compare that to the fluke 101 / 87 and 1253B ?
A GDT for example is going to read an open. Of course, who puts GDTs in meters besides the Germans! Pulled out a few MOVs and the first one I looked at was 50M. It's going to be very non-linear and there is a lot to consider when it comes to protection than just the DC resistance.
The following data was taken with the Fluke 101 that beat out all the other meters in the transient tests. I waited for reading to settle, however settling time was several minutes in many cases. I may have not waited long enough in some cases but it should give you some idea. I used banana to banana leads. Sorry but I no longer have the old 87V to check. Besides it was damaged so may have different leakage after I changed out all the diodes in it.
No batteries, Pos lead to Pos, Neg to Neg ( I know you did not ask for polarity but it will make a difference)
ACV >100M
DCV 15.2M
ACmV 3.3M
Ohms 1.6M
Cap. 1.6M
Hz 3.1M
No batteries, Pos lead to Neg
ACV >100M
DCV 12.2M
ACmV 2.4M
Ohms 8.56K
Cap. 8.56K
Hz 3.1M
Batteries installed, Pos lead to Pos, Neg to Neg
ACV >100M
DCV 11.1M
ACmV 5.5M
Ohms 3.7 - 4.4M, Cont. 1.1M, Diode 4.8M
Cap. 1.8M
Hz 5.5M, DC 5.5M
Batteries installed, Pos lead to Neg
ACV >100M
DCV 11.1M
ACmV 5.1M
Ohms 2.3K, Cont. 2.3K, Diode 570K
Cap. 183K
Hz 5.0M, DC 5.0M
There is no manual range on the 101 to see how the attenuator effects it.
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That Voltcraft VC890 is a pile of shit dressed to thrill, it's basic dc accuracy is +-0.8%, that's crap and it's boasts 60000 count :palm:
It's actually 0.03% +10 for 600mv range and 0.05% +10 for 6-1000v range
EDIT: check page 81: http://www.produktinfo.conrad.com/datenblaetter/100000-124999/124600-an-01-ml-VOLTCRAFT_VC890_OLED_DMM_de_en_fr_nl.pdf (http://www.produktinfo.conrad.com/datenblaetter/100000-124999/124600-an-01-ml-VOLTCRAFT_VC890_OLED_DMM_de_en_fr_nl.pdf)
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can i ask to measure the input impedance of the VC890 on each selector range w/o power on? and compare that to the fluke 101 / 87 and 1253B ?
VC890 - No batteries:
ACV: 5.49 M
DCV: 5.5 M
DC mV: 1 M
Ohms: 0.7 M
Cap: 0.7 M
87V - No batteries:
VAC: 8.6 M
VDC: 6.5 M
mvDC: 95 K
ohms: 98 K
U1253B - No batteries:
VAC: OL
VDC: 9.7 M
mvDC: 300 K
ohms: 250 K
cap: 250 K
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That Voltcraft VC890 is a pile of shit dressed to thrill, it's basic dc accuracy is +-0.8%, that's crap and it's boasts 60000 count :palm:
It's actually 0.03% +10 for 600mv range and 0.05% +10 for 6-1000v range
EDIT: check page 81: http://www.produktinfo.conrad.com/datenblaetter/100000-124999/124600-an-01-ml-VOLTCRAFT_VC890_OLED_DMM_de_en_fr_nl.pdf (http://www.produktinfo.conrad.com/datenblaetter/100000-124999/124600-an-01-ml-VOLTCRAFT_VC890_OLED_DMM_de_en_fr_nl.pdf)
If its just for show and collects dust, 10% is good enough. :-DD
Did you try flipping the leads and see if it made a difference on your meters?
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That Voltcraft VC890 is a pile of shit dressed to thrill, it's basic dc accuracy is +-0.8%, that's crap and it's boasts 60000 count :palm:
It's actually 0.03% +10 for 600mv range and 0.05% +10 for 6-1000v range
EDIT: check page 81: http://www.produktinfo.conrad.com/datenblaetter/100000-124999/124600-an-01-ml-VOLTCRAFT_VC890_OLED_DMM_de_en_fr_nl.pdf (http://www.produktinfo.conrad.com/datenblaetter/100000-124999/124600-an-01-ml-VOLTCRAFT_VC890_OLED_DMM_de_en_fr_nl.pdf)
If its just for show and collects dust, 10% is good enough. :-DD
Did you try flipping the leads and see if it made a difference on your meters?
I did, and it changes a bit on a few ranges, but I was feeling too lazy to report the findings. Laziness prevails!
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And some dont blow the fuse when in current mode with mains or 3 phase applied, the meter explodes instead, well my Fluke 70 series did across 2 phases whilst I was being distracted fixing a machine. If they survive this then perhaps the next level awaits.
Well done and many thanks.... :-+
Muttley
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And some dont blow the fuse when in current mode with mains or 3 phase applied, the meter explodes instead, well my Fluke 70 series did across 2 phases whilst I was being distracted fixing a machine. If they survive this then perhaps the next level awaits.
Well done and many thanks.... :-+
Muttley
I have a GreenLee 200a (Brymen 250 series meter). I got it for free because the thing didn't work. It turned out the trace from the negative terminal was blown just next to the terminal. You can see the trace I'm talking about in this picture, the negative terminal is the one just left of center in the image. The trace was blown where it extends through the isolation slots. I repaired it by soldering a bit of wire back into the gap. The fuse also blew but I was surprised to see that the blown fuse wasn't the only damage. After repairing the trace the meter as worked just fine (but I would never use it on high power systems with a repaired trace... if I ever had to do that I have an 87-5 for that job). Regardless, I am disappointed that it appears that the meter died due to a short through the high current loop. I thought the whole idea of $10 fuses was to avoid damaging the rest of the meter.
(https://www.eevblog.com/forum/testgear/brymen-bm-257-pictures-and-mini-review/?action=dlattach;attach=34054;image)
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And some dont blow the fuse when in current mode with mains or 3 phase applied, the meter explodes instead, well my Fluke 70 series did across 2 phases whilst I was being distracted fixing a machine. If they survive this then perhaps the next level awaits.
Well done and many thanks.... :-+
Muttley
I have a GreenLee 200a (Brymen 250 series meter). I got it for free because the thing didn't work. It turned out the trace from the negative terminal was blown just next to the terminal. You can see the trace I'm talking about in this picture, the negative terminal is the one just left of center in the image. The trace was blown where it extends through the isolation slots. I repaired it by soldering a bit of wire back into the gap. The fuse also blew but I was surprised to see that the blown fuse wasn't the only damage. After repairing the trace the meter as worked just fine (but I would never use it on high power systems with a repaired trace... if I ever had to do that I have an 87-5 for that job). Regardless, I am disappointed that it appears that the meter died due to a short through the high current loop. I thought the whole idea of $10 fuses was to avoid damaging the rest of the meter.
(https://www.eevblog.com/forum/testgear/brymen-bm-257-pictures-and-mini-review/?action=dlattach;attach=34054;image)
perhaps the prior user didn't replace a blown fuse with a fast blow?
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And some dont blow the fuse when in current mode with mains or 3 phase applied, the meter explodes instead, well my Fluke 70 series did across 2 phases whilst I was being distracted fixing a machine. If they survive this then perhaps the next level awaits.
Well done and many thanks.... :-+
Muttley
I have a GreenLee 200a (Brymen 250 series meter). I got it for free because the thing didn't work. It turned out the trace from the negative terminal was blown just next to the terminal. You can see the trace I'm talking about in this picture, the negative terminal is the one just left of center in the image. The trace was blown where it extends through the isolation slots. I repaired it by soldering a bit of wire back into the gap. The fuse also blew but I was surprised to see that the blown fuse wasn't the only damage. After repairing the trace the meter as worked just fine (but I would never use it on high power systems with a repaired trace... if I ever had to do that I have an 87-5 for that job). Regardless, I am disappointed that it appears that the meter died due to a short through the high current loop. I thought the whole idea of $10 fuses was to avoid damaging the rest of the meter.
(http://wwom/forum/testgear/brymen-bm-257-pictures-and-mini-review/?action=dlattach;attach=34054;image)
perhaps the prior user didn't replace a blown fuse with a fast blow?
I don't think so. The fuse I pulled out was the correct HRC fuse type. I guess they might have bypassed it then put the fuse back in when they blew the "fuse" a second time.
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Is the fuse properly rated, and if so, its not counterfeit? If the fuse was good, then the PCB is either a production batch defect or its a design defect.
Greelee claims to have limited lifetime warranties on many DMMs, including this one. Manufacturers often receive those damaged products for analysis, to improve their QC or determine if a recall is needed. In the USA, you can report it to CPSC or OSHA.
http://www.greenlee.com/products/DMM%2540c-1000V-AC%2540FDC-(DM%2540d200A).html?product_id=17750 (http://www.greenlee.com/products/DMM%2540c-1000V-AC%2540FDC-(DM%2540d200A).html?product_id=17750)
Regardless, I am disappointed that it appears that the meter died due to a short through the high current loop. I thought the whole idea of $10 fuses was to avoid damaging the rest of the meter.
70s also have limited lifetime warranties, and an event like that is also reportable to OSHA or CPSC and the meter subject to warranty.
And some dont blow the fuse when in current mode with mains or 3 phase applied, the meter explodes instead, well my Fluke 70 series did across 2 phases whilst I was being distracted fixing a machine. If they survive this then perhaps the next level awaits.
Well done and many thanks.... :-+
Muttley
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Since I have long since thrown out the fuse I can't go back and verify it wasn't a fake but I really doubt it. This damage occurred before I owned the meter so I really can't claim that the damage was the fault of a bad fuse. It really is possible someone decided to bypass the fuse, blew the meter then put the fuse (yeah boss, I have no idea why it just broke!). Perhaps the seller was had. They might have bought it thinking it worked (it did power on). When the unit arrived not working the seller gave me a refund and didn't ask for it back. Hence after fixing it it was free (plus cost of fuse) to me and so far seems like a nice meter (really nice probes). It's a great around the house meter because it has voltage detection.
Since I can't say under what circumstances it failed I don't think it would be right to accuse Brymen of a bad design.
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Yes, you are right. Glad you were able to get it working fairly easily with no added issues. It should serve you well.
Since I can't say under what circumstances it failed I don't think it would be right to accuse Brymen of a bad design.
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Watched the last three videos. Well, I watched the hold peak too. :-DD You mention you have a few different AMPROBE meters and the continuity feature is always poor on them. It's interesting to see how slow that one you have is compared with the 510 I have. On the flip side, my 101 is really slow compared with your 107.
Does make me wonder if we need to overclock some meters...
I liked you comment about just how much it is taking to make the videos. That's a lot of meters to run through. But hang in there. Your most of the way there and doing a fine job.
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Watched the last three videos. Well, I watched the hold peak too. :-DD You mention you have a few different AMPROBE meters and the continuity feature is always poor on them. It's interesting to see how slow that one you have is compared with the 510 I have. On the flip side, my 101 is really slow compared with your 107.
Does make me wonder if we need to overclock some meters...
I liked you comment about just how much it is taking to make the videos. That's a lot of meters to run through. But hang in there. Your most of the way there and doing a fine job.
Thank you sir! I recorded the Southwire, but still have to cut and upload it. Going to try to do at least one more tonight. I'm curious of how different the 107 is from the 101. I suppose you'll find out soon enough!
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I thought the whole idea of $10 fuses was to avoid damaging the rest of the meter.
FWIW, it's my understanding they're there to protect the user rather than the meter (i.e. cost of a meter vs. human injury/life situation).
Regarding your meter, congratulations on getting it working again. :-+
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I thought the whole idea of $10 fuses was to avoid damaging the rest of the meter.
FWIW, it's my understanding they're there to protect the user rather than the meter (i.e. cost of a meter vs. human injury/life situation).
Regarding your meter, congratulations on getting it working again. :-+
Most certainly that should be the most important thing! Still, you would think that once the fuse blew that would be the end of the current path. An spark inside the meter is exactly what we don't want. That BTW, really makes me think that what might have gone wrong is someone blew the fuse, jumped it then blew the meter, and finally removed the "jumper" to hide the evidence.
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https://www.youtube.com/watch?feature=player_detailpage&v=fihUrdsyddc#t=117 (https://www.youtube.com/watch?feature=player_detailpage&v=fihUrdsyddc#t=117)
Just to be clear, the 101 is what survived. I have never tested the 107, however I did run the 87V which was also damaged. The 101 I have is VERY robust. The generator ended up around 20J at 13KV. It's not can crushing energy but could be lethal. I started well under a J and still had meters fail.
Good job with your continued efforts making these videos. Looking forward to seeing the AC line voltage tests.
Joe,
I just watched a number of your videos, thanks for making them! I did have a quick question about the cheap meter CAT 1 testing. You noted the meters that failed to function after a CAT 1 test and then noted the meters were "rated" at CAT 2 or even 3 (The Mastec is the one where this caught my attention). I thought the CAT ratings simply mean the meter will not harm the user when subjected to the test. I thought failure to function was OK. Am I wrong in thinking that all of the meters you tested "passed" at least that part of the CAT 1 test since none caught fire, exploded etc?
I was thinking about this because one of your videos linked to one of mjlorton's videos where Fluke engineers show a cheap meter exploding
https://www.youtube.com/watch?v=OEoazQ1zuUM (https://www.youtube.com/watch?v=OEoazQ1zuUM)
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Joe,
I just watched a number of your videos, thanks for making them! I did have a quick question about the cheap meter CAT 1 testing. You noted the meters that failed to function after a CAT 1 test and then noted the meters were "rated" at CAT 2 or even 3 (The Mastec is the one where this caught my attention). I thought the CAT ratings simply mean the meter will not harm the user when subjected to the test. I thought failure to function was OK. Am I wrong in thinking that all of the meters you tested "passed" at least that part of the CAT 1 test since none caught fire, exploded etc?
I was thinking about this because one of your videos linked to one of mjlorton's videos where Fluke engineers show a cheap meter exploding
https://www.youtube.com/watch?v=OEoazQ1zuUM (https://www.youtube.com/watch?v=OEoazQ1zuUM)
Thanks. Glad you enjoyed them. During the time I was making them, I was asked several times about the design of my transient generator. You want to know how to make a KJ test jig at home?? I know how and will give you my secret. Start with a 20J test jig, add some ignorance and drama to it. There you have it, instant high risk death machine capable of exploding meters and causing fires! :-DD :-DD
I don't believe I ever claimed to test to an IEC standard, nor was it ever my intent to. These were very low energy stress tests ran only to see how robust the meters were. Well, that and provide some entertainment. I did however provide details about each setup as I went through it. If you would like to know if a specific meter met it's CAT rating, you would need to go to an accredited lab.
As for your question, I would contact some manufactures and see what you can find out. It was covered but I don't believe you will get a clear answer.
If 5ky does decide he would like to give up his meters for another round of destructive testing (I think he said $600 or something out of pocket) to help us learn more about how robust these meters are, I will continue to test them from a low energy source. I would be willing to bet 5ky is starting to think that the time invested is worth more than the cash. :-DD
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Joe,
I just watched a number of your videos, thanks for making them! I did have a quick question about the cheap meter CAT 1 testing. You noted the meters that failed to function after a CAT 1 test and then noted the meters were "rated" at CAT 2 or even 3 (The Mastec is the one where this caught my attention). I thought the CAT ratings simply mean the meter will not harm the user when subjected to the test. I thought failure to function was OK. Am I wrong in thinking that all of the meters you tested "passed" at least that part of the CAT 1 test since none caught fire, exploded etc?
I was thinking about this because one of your videos linked to one of mjlorton's videos where Fluke engineers show a cheap meter exploding
https://www.youtube.com/watch?v=OEoazQ1zuUM (https://www.youtube.com/watch?v=OEoazQ1zuUM)
Thanks. Glad you enjoyed them. During the time I was making them, I was asked several times about the design of my transient generator. You want to know how to make a KJ test jig at home?? I know how and will give you my secret. Start with a 20J test jig, add some ignorance and drama to it. There you have it, instant high risk death machine capable of exploding meters and causing fires! :-DD :-DD
I don't believe I ever claimed to test to an IEC standard, nor was it ever my intent to. These were very low energy stress tests ran only to see how robust the meters were. Well, that and provide some entertainment. I did however provide details about each setup as I went through it. If you would like to know if a specific meter met it's CAT rating, you would need to go to an accredited lab.
As for your question, I would contact some manufactures and see what you can find out. It was covered but I don't believe you will get a clear answer.
If 5ky does decide he would like to give up his meters for another round of destructive testing (I think he said $600 or something out of pocket) to help us learn more about how robust these meters are, I will continue to test them from a low energy source. I would be willing to bet 5ky is starting to think that the time invested is worth more than the cash. :-DD
I'm done recording--just need to do the cutting, then I can do the drop tests and the mains on ohms, then I'll send the survivers to you for some more "love". :-+
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I'm all caught up. Looking forward to seeing them!
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Seriously mods....can we get this pinned/stickied to the top of the Test Equipment sub-forum? I think it's worthy of it - and will help a lot of people out.
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5ky, you're moving too quick. Watched the Southwire and saw you have the UEI up now. I can't keep up! :-DD
I sketched up the design for the new generator and ran some simulations on it over the last couple of days. I still need to pick a new connector, test out the switch design and if that works, order parts. Depending how the testing goes, maybe 5 weeks out unless I get really motivated. So take your time!!
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Made a very small amount of progress on the new transient generator. While testing, I ended up damaging one of my power supplies. Had to order a few parts to make the repairs so I ordered the first parts for the new generator as well.
I often wonder how well these fancy modern supplies would hold up to my tortures of home hobby use. Over the years, I have damaged more power supplies than any other test equipment. This one is getting some transorbs this time to hopefully harden it a bit.
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Made a very small amount of progress on the new transient generator. While testing, I ended up damaging one of my power supplies. Had to order a few parts to make the repairs so I ordered the first parts for the new generator as well.
I often wonder how well these fancy modern supplies would hold up to my tortures of home hobby use. Over the years, I have damaged more power supplies than any other test equipment. This one is getting some transorbs this time to hopefully harden it a bit.
Nice! What goes into a transient generator? Cap bank and SCR to fire it with?
I'm about to wrap up the last multimeter review, and then it's mains on ohms time, then drop tests in the garage. I doubt I'll get this all cut and uploaded today, but in the next few days I would imagine. Then I'll put the meters in a plastic tote in the basement where they'll live until you give me the green light to mail them to you. :-DMM
UPDATE: Mains on ohms (technically i swept the entire range on each meter) testing is done. Just have to head to the garage to do drop tests. I considered doing slow-mo and stuff, but that requires really good lighting and extra work so I'm not sure if I'll go through all that trouble when I can drop just it and show the results :-DD
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Nice! What goes into a transient generator? Cap bank and SCR to fire it with?
I'm about to wrap up the last multimeter review, and then it's mains on ohms time, then drop tests in the garage. I doubt I'll get this all cut and uploaded today, but in the next few days I would imagine. Then I'll put the meters in a plastic tote in the basement where they'll live until you give me the green light to mail them to you. :-DMM
I gave a few links that gave the basic generator. One had a SPICE model. My first ones were very simple as there has been no AC carrier and no polarity switching. Switching can be done any number of ways. This is actually what I was working on when I damage my power supply. For the capacitors, you just need to pay attention to the data sheets. The one member showed a video inside of their commercial unit. It was pretty interesting. Their system also did not couple to the AC line. I'll put together some videos of the generator once it starts to go together.
Where any of the meters damaged in the AC line test?..... No, never mind. Don't spoil it!! :-DD :-DD
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found it
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/ (https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/)
thanks again joeqsmith for his experiments :P and of interest to me n some others is the surge generator :P
Yeah it was pretty neat IMO.
Wonder if the DMM's 5ky will send Joe will continue the kitty kitty thread or be part of this one? :-//
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Mains on all ranges uploaded. Got drop tests recorded but didn't have time to record the aftermath. The slow motion turned out much better than I had expected. Hopefully I'll have that uploaded tonight.
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Good video. As long as the meters are just sitting there, maybe you could verify that all of the functions still work, not just the AC volts and run them at the same line voltage Dave does.
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Good video. As long as the meters are just sitting there, maybe you could verify that all of the functions still work, not just the AC volts and run them at the same line voltage Dave does.
I will verify that each works tonight. (a few had some rattles after the drop tests) I wish I had an easy way to test with 240 vac without going to the breaker box
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Easier and safer would be to use a transformer. You can also use a variac, not as safe. That is if you have one or the other.
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Easier and safer would be to use a transformer. You can also use a variac, not as safe. That is if you have one or the other.
Aren't variacs generally step down? I wasn't aware you could get ones that are wound to go higher than the input. If so, I need to do some shopping tonight!
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Easier and safer would be to use a transformer. You can also use a variac, not as safe. That is if you have one or the other.
Aren't variacs generally step down? I wasn't aware you could get ones that are wound to go higher than the input. If so, I need to do some shopping tonight!
Some variacs ranged 0-100% of the input AC voltage. However popular also were tapped primary where the secondary would range like 0-125% because the input AC was applied between one end and the tap lower from the other end of the winding.
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With care, and I mean extreme care, you can use a variac backwards. You have to pay attention and understand the risks, but it can be done. You need to not exceed the VA rating and pay special attention that you don't turn the dial too far and basically cause a short on the variable tap while using it as an input. It would be best to put a fuse in line with the variable tap before using it as an input.
And read my words again, EXTREME CARE. This is not a very safe thing to do.
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Don't buy anything just to run this test. I can run them at 220 or whatever. It would be interesting to hear if they all do still work. No need to make another video, just a quick test.
Also, I am not sure if it matters but when I ran these tests, I would run the meters through all of their modes. For example, diode continuity resistance may be on one switch setting, so I would cycle through them. My thinking was the the input protection may behave differently for the various modes.
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Don't buy anything just to run this test. I can run them at 220 or whatever. It would be interesting to hear if they all do still work. No need to make another video, just a quick test.
Also, I am not sure if it matters but when I ran these tests, I would run the meters through all of their modes. For example, diode continuity resistance may be on one switch setting, so I would cycle through them. My thinking was the the input protection may behave differently for the various modes.
I went back and ran them all on each individual range on mains to be sure. I'm about to test each meter to see if they took any damage and then I'll cut and upload the drop tests and final results tonight. I heard a few rattles after the drops, but I think those are fuses that popped out, but we shall see!
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Nice job @5ky. Really well done series of reviews.
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Took me a month, but I finally got it all done. The drop tests video is uploaded and viewable now: (but still processing for the higher resolutions): https://www.youtube.com/watch?v=VslGl2rc3U4 (https://www.youtube.com/watch?v=VslGl2rc3U4)
The slow motion shots turned out great for being in a dark garage and being recorded by an iPhone :-DD
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Thanks for the videos. I would like to point out one thing if I may. The IEC tests are for a drop to a hard wood floor, not concrete, if I remember correctly. But this shows at least a fairly consistent test between models.
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Thanks for the videos. I would like to point out one thing if I may. The IEC tests are for a drop to a hard wood floor, not concrete, if I remember correctly. But this shows at least a fairly consistent test between models.
While I do have oak floors in my kitchen/dining rooms--my wife would murder me if I did the drop tests on them :-DD
EDIT: This makes me wonder why they chose wood for their testing. I wonder if it's the most common floor type that multimeters would face in the real world?
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Many physical and environmental toughness tests are offshoots from US military requirements, i.e., MILSPEC. There are many drop tests but most have to do with quantifying the amount of shock [e.g. newtons ] and the shape of the curve from the response. For hand helds, IIRC, drop tests are multiple times each corner, top, back, and face of device.
Military tests test suitability when dropped or shaken around a wooden crate, say it came loose from its mounting, drop to a wooden floor by a user as field deployment barracks have wooden, dirt or sand floors, and drop by something like a parachute.
I'm not sure why the drop onto wood floors translated to suitability for civilians onto concrete or tiled floors, maybe its because during testing on wood its done 20+ times.
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Nice job 5KY.
A couple of comments.
While I applaud all the testing you did, I did not expect any failures on mains up to 120V. I also would not expect any up to 240V. But, over 240V, I would expect some. I once had a Uni-Trend meter that did have PTC protection on the front end to handle Mains. But, when I looked it up, it was rated to 250V. If any of those meters have these 250V PTC's, they should all handle your testing, but may not be able to go to the 600V they are supposed to.
For the drop testing, I agree that it was supposed to be to wood, but that does not mean using your wood floors. All you would need is a piece of plywood that you lay on the concrete. I watched some Fluke videos where the wood was just laying on the floor, and you could see it bounce up when a meter hit it. I also saw some Klein videos where they are dropping to steel, and the steel is not a flat surface, which is about as tough as you can get to pass. But, they are using that to go beyond the standard. They even have a video that they drop a meter 40 feet from a bucket truck onto pavement.
I agree that losing the fuses at 3 feet seems bad. I would think all meters should be able to handle that. The B&K case breaking really surprised me. I expected better from them.
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Nice job 5KY.
A couple of comments.
While I applaud all the testing you did, I did not expect any failures on mains up to 120V. I also would not expect any up to 240V. But, over 240V, I would expect some. I once had a Uni-Trend meter that did have PTC protection on the front end to handle Mains. But, when I looked it up, it was rated to 250V. If any of those meters have these 250V PTC's, they should all handle your testing, but may not be able to go to the 600V they are supposed to.
For the drop testing, I agree that it was supposed to be to wood, but that does not mean using your wood floors. All you would need is a piece of plywood that you lay on the concrete. I watched some Fluke videos where the wood was just laying on the floor, and you could see it bounce up when a meter hit it. I also saw some Klein videos where they are dropping to steel, and the steel is not a flat surface, which is about as tough as you can get to pass. But, they are using that to go beyond the standard. They even have a video that they drop a meter 40 feet from a bucket truck onto pavement.
I agree that losing the fuses at 3 feet seems bad. I would think all meters should be able to handle that. The B&K case breaking really surprised me. I expected better from them.
Turns out, the BK wasn't broken. Fuse popped out and the 10amp input jack sleeve popped loose and wedged the corner of the chassis open. Once I used pliers to get the input jack plastic sleeve back into place, as well as the fuse, it reassembled back to normal. Not acceptable for a 1M drop, but it technically didn't break.
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5ky, thanks for all the good work. I agree with Meter Junkie's critique, but your test was very informative since all the meters were given the same treatment.
Technically, I think meters with popped off fuses failed the drop test. IIRC the procedure, meters are inspected for hazards and subjected to a voltage withstand test after the drop, and had the inspection not found fuses had dislodged, it would easily cause some events during a voltage test. The voltage test could reveal subtle breaks, such as trace cracks, that could be missed visually.
A meter falling off a table or a ladder is fairly common, particularly doing a setup just before probing, particularly in marked hazards in the testing environment. If the fuses didn't make a sound yet dislodged, that's most concerning.
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5ky, thanks for all the good work. I agree with Meter Junkie's critique, but your test was very informative since all the meters were given the same treatment.
Technically, I think meters with popped off fuses failed the drop test. IIRC the procedure, meters are inspected for hazards and subjected to a voltage withstand test after the drop, and had the inspection not found fuses had dislodged, it would easily cause some events during a voltage test. The voltage test could reveal subtle breaks, such as trace cracks, that could be missed visually.
A meter falling off a table or a ladder is fairly common, particularly doing a setup just before probing, particularly in marked hazards in the testing environment. If the fuses didn't make a sound yet dislodged, that's most concerning.
Definitely. I think they should mold something on the other side of the chassis that nearly touches the fuse so that while the chassis is assembled, the fuses can't go anywhere. It would be simple to implement and effective.
As for testing with 240vac and on wood--I just emulated the benchmark: Dave's shootouts. (only I don't "easy" access to 240 vac)
I figured if I copy the things he tests, it'll be easier to compare meters that I reviewed versus the ones he reviewed.
Unrelated note: I noticed that tester.co.uk had the hioki dt4282 for cheaper than I've seen it anywhere and had a moment of weakness. (it arrives tomorrow)
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5ky, thanks for all the good work. I agree with Meter Junkie's critique, but your test was very informative since all the meters were given the same treatment.
Technically, I think meters with popped off fuses failed the drop test. IIRC the procedure, meters are inspected for hazards and subjected to a voltage withstand test after the drop, and had the inspection not found fuses had dislodged, it would easily cause some events during a voltage test. The voltage test could reveal subtle breaks, such as trace cracks, that could be missed visually.
A meter falling off a table or a ladder is fairly common, particularly doing a setup just before probing, particularly in marked hazards in the testing environment. If the fuses didn't make a sound yet dislodged, that's most concerning.
Definitely. I think they should mold something on the other side of the chassis that nearly touches the fuse so that while the chassis is assembled, the fuses can't go anywhere. It would be simple to implement and effective.
As for testing with 240vac and on wood--I just emulated the benchmark: Dave's shootouts. (only I don't "easy" access to 240 vac)
I figured if I copy the things he tests, it'll be easier to compare meters that I reviewed versus the ones he reviewed.
Unrelated note: I noticed that tester.co.uk had the hioki dt4282 for cheaper than I've seen it anywhere and had a moment of weakness. (it arrives tomorrow)
I think many do. However, some like the Uni-T's clearly are designed for more than one fuse type. The direct from China models seem to feature really small fuses while the retail for Europe models often have larger fuses. I've also seen this in some Brymens. A while back I did a tear down on a Brymen/Amprobe AM120 ( https://www.eevblog.com/forum/testgear/amprobe-%28bryman%29-am130-teardown/msg311314/#msg311314 (https://www.eevblog.com/forum/testgear/amprobe-%28bryman%29-am130-teardown/msg311314/#msg311314) ). Anyway, it used smaller fuses vs the larger bus sized ones like you see in a Fluke 87. The case was clearly designed to handle both types as shown in this AM270 tear down ( https://www.eevblog.com/forum/testgear/teardown-amprobe-am-270-digital-multimeter/msg70056/#msg70056 (https://www.eevblog.com/forum/testgear/teardown-amprobe-am-270-digital-multimeter/msg70056/#msg70056) ). I did see that my Fluke 187 does have plastic ribs above the fuses to keep them in place.
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5ky, thanks for all the good work. I agree with Meter Junkie's critique, but your test was very informative since all the meters were given the same treatment.
Technically, I think meters with popped off fuses failed the drop test. IIRC the procedure, meters are inspected for hazards and subjected to a voltage withstand test after the drop, and had the inspection not found fuses had dislodged, it would easily cause some events during a voltage test. The voltage test could reveal subtle breaks, such as trace cracks, that could be missed visually.
A meter falling off a table or a ladder is fairly common, particularly doing a setup just before probing, particularly in marked hazards in the testing environment. If the fuses didn't make a sound yet dislodged, that's most concerning.
Definitely. I think they should mold something on the other side of the chassis that nearly touches the fuse so that while the chassis is assembled, the fuses can't go anywhere. It would be simple to implement and effective.
As for testing with 240vac and on wood--I just emulated the benchmark: Dave's shootouts. (only I don't "easy" access to 240 vac)
I figured if I copy the things he tests, it'll be easier to compare meters that I reviewed versus the ones he reviewed.
Unrelated note: I noticed that tester.co.uk had the hioki dt4282 for cheaper than I've seen it anywhere and had a moment of weakness. (it arrives tomorrow)
I think many do. However, some like the Uni-T's clearly are designed for more than one fuse type. The direct from China models seem to feature really small fuses while the retail for Europe models often have larger fuses. I've also seen this in some Brymens. A while back I did a tear down on a Brymen/Amprobe AM120 ( https://www.eevblog.com/forum/testgear/amprobe-%28bryman%29-am130-teardown/msg311314/#msg311314 (https://www.eevblog.com/forum/testgear/amprobe-%28bryman%29-am130-teardown/msg311314/#msg311314) ). Anyway, it used smaller fuses vs the larger bus sized ones like you see in a Fluke 87. The case was clearly designed to handle both types as shown in this AM270 tear down ( https://www.eevblog.com/forum/testgear/teardown-amprobe-am-270-digital-multimeter/msg70056/#msg70056 (https://www.eevblog.com/forum/testgear/teardown-amprobe-am-270-digital-multimeter/msg70056/#msg70056) ). I did see that my Fluke 187 does have plastic ribs above the fuses to keep them in place.
I suppose a piece of foam would work too, to accommodate for the different size fuse situation. Anything would be better than fuses popping out like that from a 1M drop.
This makes me want to go take all my meters apart to see if any of them have something on the other end of the chassis to hold the fuse in place.
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Yeah, I don't look at 1m as that far. I know Motorola's old cell phones were rated at 1.8M to concrete (it was OK for the battery and door to come off if they could be put back on). I generally expect 1m (at least to wood) to function the whole time.
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Its safer to mold a piece of rigid ABS plastic stuck on the opposite section of the case right atop the fuses to keep them from popping out, foam could melt or burn with heat, or it will deform with age and lose it compressive quality.
For 240Vac, the typical source in most US homes are large appliances, wash dryers, heat pumps etc., if they are plugged in. They are NEMA 10-30R sockets, the setup is 120V, Ground, 120V. Note you are in CAT III territory therein so work safe.
(http://www.cooperindustries.com/content/dam/public/wiringdevices/products/images/_3/38b_sp_220.jpg)
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Watched the last video. Job well done. I am not sure why they don't use better fuse holders. That thin stamped crap bends pretty easy and takes a set. Picture shows the ones I used to replace the junk in the Mastech. They cause the fuse sit up a little higher but did not interfere with the back cover.
So everything worked in all the modes. I guess I too am not surprised. Even if you ran them at 220, I doubt there would be any problems. I ran a few on a 600ish volt DC supply and the ones I tested did not pull a lot of current.
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A few of them had decent fuse holders but it seemed the majority used the really weak ones similar to the ones that failed from the drop.
The only 230 plug I have in my home is behind my dryer, and I'm far too lazy to pull it out just for testing the meters :-DMM
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A few of them had decent fuse holders but it seemed the majority used the really weak ones similar to the ones that failed from the drop.
The only 230 plug I have in my home is behind my dryer, and I'm far too lazy to pull it out just for testing the meters :-DMM
No problem. I am thinking to add some sort of built-in bias supply to the new generator. Started out thinking of just using a transformer but now I am thinking of some sort of ARB that can do +/-KV sort of thing. Lot's of different ideas but still focusing on proving out the basic parts. Have made a little progress. I'll post a video of it sometime today.
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A few of them had decent fuse holders but it seemed the majority used the really weak ones similar to the ones that failed from the drop.
The only 230 plug I have in my home is behind my dryer, and I'm far too lazy to pull it out just for testing the meters :-DMM
No problem. I am thinking to add some sort of built-in bias supply to the new generator. Started out thinking of just using a transformer but now I am thinking of some sort of ARB that can do +/-KV sort of thing. Lot's of different ideas but still focusing on proving out the basic parts. Have made a little progress. I'll post a video of it sometime today.
I saw the video today and it looks like it's going to be a pretty flexible little rig!
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I bet your wife is getting tired of seeing that tub of meters laying around taking up space.
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I bet your wife is getting tired of seeing that tub of meters laying around taking up space.
"yeah, a little bit" ~wifey
Take your time man, it's all good :-+