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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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13th Jul 2017, 10:49 pm | #21 |
Octode
Join Date: Jul 2014
Location: Petersfield, Hampshire, UK.
Posts: 1,043
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Re: Cheap multimeters
One thing I find annoying with cheap meters is the delay when using the continuity function
Waiting for that beep when chasing shorts is frustrating ! Is there a delay with your £15 meter ? |
13th Jul 2017, 11:00 pm | #22 |
Dekatron
Join Date: Jul 2007
Location: Evesham, Worcestershire, UK.
Posts: 4,241
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Re: Cheap multimeters
Good question - I don't think I've commented on that anywhere so far...
It's excellent. Subjectively, it's much the same as my Fluke 87V. I suppose I could set up a test with a function generator to determine the minimum time needed to trigger the bleeper, but I'm not sure it's needed. Suffice to say, I've been using the AN8002 for some months now, and have never noticed any problem. |
14th Jul 2017, 3:46 pm | #23 |
Dekatron
Join Date: Jul 2007
Location: Evesham, Worcestershire, UK.
Posts: 4,241
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Re: Cheap multimeters
Well, Dave Jones has just done a review:
https://www.youtube.com/watch?v=xdGQEVdxmQQ Overall, he's critical of the lack of obvious safety features (hardly a surprise), but is impressed with the functionality. I don't think he points out anything that I haven't already mentioned here or on the other places I've been posting about it, but the video is still a good summary. I think he could have placed more emphasised on the functionality for the price. Perhaps that's because he largely ignores the meters at this price point, whereas I've been studying them for a while? In short, before these Aneng/Zotek meters came on the scene, this money would only get you 2000-count meters - certainly not 6000 or 9999-count meters, and definitely not true-RMS. I also wonder if he's seen Joe Smith's review of the AN8002? That meter seems a lot more robust that appearances would suggest, and I've no reason to suspect the AN8008 will be any different. Anyway, things have certainly moved on a bit in this end of the market. Mark |
14th Jul 2017, 8:18 pm | #24 |
Dekatron
Join Date: Jun 2016
Location: London, UK.
Posts: 3,687
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Re: Cheap multimeters
Indeed. I can't wait until I get can get a cheap 5.5/6.5 digit. It's a pain trimming offsets on a 4.5 digit. I've got an HP 3478 but it's not calibrated so I can't really trust it.
This kills me. Even the recent flukes are horrible. The continuity is derived post ADC so you have to wait for it to integrate. I think it's derived off whatever does the bargraph sampling on the newer ones. Got to be honest my goto meter is a fluke 8024b; its faster than a seagull on chips and it has a monostable to stretch the beeps. Reckon it'll trigger in a few ns. |
14th Jul 2017, 8:24 pm | #25 | ||
Heptode
Join Date: Jun 2009
Location: St Helens, Lancashire, UK.
Posts: 641
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Re: Cheap multimeters
Quote:
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People who are in the market for such cheap meters may not understand all the limitations, particularly safety, and the risks involved with such meters. Amateurs and hobbyists are the ones most likely to make mistakes, and such a meter could be very unforgiving if connected up to a high energy circuit by accident. I think forgiving cheap meters of basic safety features because they are cheap is very dangerous and possibly a little irresponsible. I know they are available to anyone, and we cant change that, but encouraging the use of potentially unsafe equipment is a pet hate of mine I would rather encourage someone to purchase quality tools that are well engineered and safe to use. Peter
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14th Jul 2017, 8:27 pm | #26 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
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Re: Cheap multimeters
People here may denigrate these cheap DMMs for not being supplied with 'proper' HRC fusing or CATIII-rated probes, yet we also have those who would be happy to probe a 100A service incomer with an AVO8.
I wonder how an AVO8 would compare in terms of electrical safety with these Tenner-from-China DMMs?? |
14th Jul 2017, 9:05 pm | #27 | |
Octode
Join Date: Oct 2003
Location: Newbury, Berkshire, UK.
Posts: 1,770
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Re: Cheap multimeters
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We have had this discussion before and there are definitely 2 camps. I don't think either side will convince the other. With respect to the AVO 8, I would imagine it is just as capable of causing a Arc Flash as a cheap Chinese multimeter, but I would have thought the chances of one being used by an unaware DIY'er would be far less than a Chinese "cheapo" by dint of the availability and low cost of the latter.
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14th Jul 2017, 10:27 pm | #28 |
Dekatron
Join Date: Jun 2016
Location: London, UK.
Posts: 3,687
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Re: Cheap multimeters
You can cause an arc flash with a Fluke 28 Ex. Most of the risks are procedural rather than equipment related. Risk assessment should be done before you do something even if it's a quick head check. It really annoys me when you see people on Dave Jones' forum thinking that the purchase of a Fluke 87V will guard them unconditionally from the evil spirit of electricity. I reckon about 80% of the stupid things you can do, the meter won't protect you and 99% of the stupid things you can do are solved with safety procedures.
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15th Jul 2017, 12:08 am | #29 | |
Dekatron
Join Date: Jul 2007
Location: Evesham, Worcestershire, UK.
Posts: 4,241
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Re: Cheap multimeters
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My turn to get on the Look back at my past posts - I am often the first person to raise the question of safety. And, I have far too many Fluke multimeters, as the pictures in this thread show: http://www.vintage-radio.net/forum/s...d.php?t=124491 During this thread, I have mentioned safety at every opportunity - I have been very clear that this is a meter for low energy electronic bench work only. David Jones says exactly the same in his video today. Despite the fact that the AN8002 appears to be more robust than a Fluke 87V in some regards, but anyway... In fact, it is actually part of my day job to teach people the dangers of unsafe multimeters. I play those arc-flash videos! And as mentioned earlier, we buy Fluke (and have a few of the RS Pro RS14, although that one hasn't been independently certified, so we only have them for their uA range). So I really don't feel that it's appropriate or fair to criticise me for recommending a decent cheap multimeter for electronic bench use by a hobbyist, given how clear I've been about safety (not just in this thread, but countless others in the past). The fact remains that a significant proportion of the membership here use those horrid DT830 meters, and it's highly unlikely they'd be persuaded to spend many hundreds of pounds on a Fluke or Keysight. So what should we do? We could keep on preaching - which no-one likes, and will achieve nothing but bad feeling - or we could accept that folk have different priorities, and try to offer them better tools within their means (with the appropriate caveats). I'd like to think that my detailed review of these meters (unfortunately spread across 3 forums, but soon to be brought together on my own website) will be of value to anyone looking for a cheap-but-good multimeter for electronic bench work. Certainly, the AN8002 or AN8008 is undeniably a massive series step up in terms of functionality and quality compared to those, and for a ridiculously low price. Dave Jones was astonished at the resolution and accuracy of the AN8008 compared to his Keysight 7.5 digit multimeter. And please note that in post #8, I recommended the £40 Fluke 101, which has passed all of Joe Smith's torture tests and will have been independently certified, making the point that safety is hopefully affordable to most/all. Though ultimately, as MrBungle so rightly says, safety is primarily a function of the user. Just look at what else you can get for £15 delivered. This meter sets a new standard, and all the other 2000-count, non true-RMS meters at that price point suddenly look rather silly. Personally, I thought this was exciting news. Frankly, I'd pay double this price - and double again if they fitted better terminals, better fuses, and a MOV or two. |
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15th Jul 2017, 2:05 am | #30 |
Heptode
Join Date: Jan 2004
Location: Stockport, Greater Manchester, UK.
Posts: 827
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Re: Cheap multimeters
I appreciate your bringing this meter to my attention.
It would be useful at work (on equipment supplied from 24V DC) if any of the suppliers on "the system" eventually stocks it. For personal use, the worst conditions would be: 1. mains through a 13-A plug fuse in series with a 30-A rewireable fuse and an 80-A supplier's cartridge fuse, 2. a valve frequency changer oscillator's anode (has seen off one cheap DMM), 3. about 750V AC across an HT winding. |
15th Jul 2017, 8:32 am | #31 | |
Octode
Join Date: Oct 2003
Location: Newbury, Berkshire, UK.
Posts: 1,770
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Re: Cheap multimeters
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White it's obviously the case that following the correct procedure minimises the risks greatly, a properly designed meter reduces the risk of dire consequences if you do something daft. Given that we all occasionally do daft things, this is a big deal ! Then there is the case of transients. Even if you are doing all the right procedural things, a transient can cause a Arc Flash. A properly designed meter reduces the risk substantially.
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15th Jul 2017, 11:35 am | #32 | |
Dekatron
Join Date: Jul 2007
Location: Evesham, Worcestershire, UK.
Posts: 4,241
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Re: Cheap multimeters
Quote:
The highest AC voltage is 750V. You might be OK with that as it is a low-energy situation, but as we saw in Dave's video, the meter says "OL" when it reaches 750V. As the AN8002 survived 2.5kV pulses in Joe Smith's tests, it's likely no harm will be done to the meter - and the MELF resistors used in the divider network are known to be rugged and reliable - but obviously you won't know by how much you've exceeded 750V when it happens. Regarding mains on the bench, that's a CAT II situation. In theory, the meter is rated to 1000V CAT II, but of course, it's not been independently verified. I'd be more circumspect about this, especially as you mention a 13A fuse rather than a 3A fuse, or a smaller mains fuse in the equipment under test. If you were unsure, then it might be worth considering fused test probes. Unfortunately, these will likely cost more than the meter, but it's worth having a set in the workshop for use with any meter when safety is a worry. Of course, these bring their own danger when their fuse blows, so test them every time before use (as we should with any meter anyway). The better ones include a high value bypass resistor so they continue to give an approximate reading when the fuse has blown. A non-contact "voltstick" is also useful to have around when working with the mains... This reminds me (I've told this story before) about the £40 Tenma meters we bought from Farnell about 10 years back. The OEM was Uni-T. I would say that the build quality was actually worse than these Aneng meters. They lasted about 3 years with really light use in an electronics classroom before developing various faults. One of them had a brilliant failure mode - it would simply lock up at random times. There was no clue about this. If you stuck the probes on anything, the display would sit there obstinately saying "0.000V". This was obviously lethal, and could have led to a series incident if an electrician was trusting it to determine if a circuit was live or not. Would I buy one of these Aneng meters for work? No, absolutely not. Even if you issued strict instructions about its intended use, what if someone borrows it? I've seen that happen many years ago, when the electricians couldn't find their own, so "borrowed" one of our cheap ones. Luckily, no serious harm was done, but it taught us all a lesson. If something went wrong in a big way and the HSE discovered that the cause was a Chinese meter from eBay, I really don't think that would end well. Obviously, I don't know where you work, but even so, that's my advice. Buy something from a reputable supplier, and choose a manufacturer that gets its meters independently tested (the CAT ratings scheme is self-declaring, which is why there are so many cheap meters with "optimistic" ratings). That gives you a paper trail that shows you've done your "due diligence". Anything else just isn't worth the risk. Low energy electronics bench work only. These meters have a great feature-set for that sort of work - that's their application. You don't need a 9999-count, 1uV resolution meter for electrical work. Right tool for the job, and all that |
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15th Jul 2017, 12:22 pm | #33 |
Retired Dormant Member
Join Date: Aug 2014
Location: Emley Moor, West Yorkshire, UK.
Posts: 92
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Re: Cheap multimeters
Ive been reading this thread with great interest, as Im in the market for a couple of new meters, but want something more reliable than the el-cheapo's ive been using recently. I have a pair of the DT-830s which tend to conflict with each other as to the reading! and an old 'workzone' machine from Aldi which is falling apart.
As much as i'd love to own a Fluke 77 or the like, they are well beyond my means! How accurate have you found these AN8008's? That is my main concern. I can budget for up to around £30, which could mean either one particularly good machine, or a pair of decent, which would really be more use. One thought is an AN8008 for its higher count and better low current ranges, and perhaps an AN8002 for the thermocouple option (usefull in the circuits I build!), assuming I can find a seller who does supply the temp probe with the unit. Do you have any recommendation regarding the low cost clamp meters? |
15th Jul 2017, 1:20 pm | #34 |
Dekatron
Join Date: Jul 2007
Location: Evesham, Worcestershire, UK.
Posts: 4,241
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Re: Cheap multimeters
I've found the accuracy to be well in excess of the published specification. I've compared them to various Flukes and my Keithley 2015THD. Dave Jones found the same - he was impressed!
What we can't say at this stage is how well they'll hold their calibration. The expensive meters are very stable over time; cheap ones might not be. I'll certainly keep an eye on it. I've been use these meters daily - often instead of Fluke - because of their small size which makes them great for bread-boarding circuits, so if I discover a problem further down the line, I'll certainly flag it up. I'd go with your suggestion to get one of each. Often it's handy to have more than one DVM, and it saves having to weigh up the pros and cons of each. I find the fact they are such different colours helps when you're measuring two things at once Remember: low-energy use only Regarding clamp meters, I've just bought a Uni-T UT210E. This is about £30 - mine came from Amazon. While I've not yet had a chance to fully investigate it yet, I chose it because it does DC as well as AC, and is the only sensibly-priced clamp meter to have 1mA resolution on DC (usually 10mA is as good as it gets). The accuracy isn't fantastic at those low currents, but that's because the fields are so very small at that level. You have to "zero" the meter while you're holding it in position to reduce the influence of stray magnetic fields. But despite that, this could be a really useful meter for all sorts of things, including car electrics. Oh, and in addition to that, it's got NCV (non-contact voltage) detection. So you only have to wave it near a wire to see if it's live or not. It's also true-RMS. I wonder if it uses the same chipset as these Aneng meters? There's lots of information out there about this unit, so don't just listen to me Hope this helps, Mark |
15th Jul 2017, 2:04 pm | #35 | |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,637
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Re: Cheap multimeters
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15th Jul 2017, 4:35 pm | #36 |
Nonode
Join Date: Jul 2010
Location: Folkestone, Kent, UK.
Posts: 2,172
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Re: Cheap multimeters
Thanks for the thread Mark, very informative. I recently bought a UT210E and like it a lot for the dosh, in my case £23 The main attraction for me was the ability to remotely read down to mA, which this meter does
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15th Jul 2017, 4:54 pm | #37 |
Guest
Posts: n/a
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Re: Cheap multimeters
I still like (and have three) the Maplin analogue meter, does all I want on a 'hobby' basis. http://www.maplin.co.uk/p/mt-2017-la...E&gclsrc=aw.ds It has fuses albeit plain glass, and the buzzer function is instantaneous, I do like the Fluke continuity test of some of the older meters where a short (in time) make gave a bit of a beep and a short break gave a larger break in the tone, this was done (in the case of my meter given to me while an apprentice some 30 odd years ago) on a separate PCB with a dual CMOS monostable on it.
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15th Jul 2017, 6:24 pm | #38 |
Nonode
Join Date: Mar 2013
Location: Leicester, UK
Posts: 2,505
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Re: Cheap multimeters
I have had a Maplin Precision Gold now for several years and gets used in all sorts of situations where it has occasionally suffered knocks and bumps. It has served me well but it recently needed adjustment and I found that the relevant adjustment pot seems difficult to position accurately. Although the meter is still working fine, I can't entirely trust that the measurement is accurate, particularly for current measurements so I was thinking of replacing it. For this reason the meter in the opening post seems interesting, but in the meantime I have also seen a Fluke 25 complete with case, manual and probes for £30, and a Fluke 16 for a similar price. I think the 16 has the advantage of true RMS. Taking onboard the comments made about cheap meters I am now uncertain whether to go a cheap meter, the Fluke 16 with true RMS or the 'bombproof' Fluke 25? Decisions decisions!
Last edited by WaveyDipole; 15th Jul 2017 at 6:29 pm. |
15th Jul 2017, 6:40 pm | #39 |
Dekatron
Join Date: Jul 2007
Location: Evesham, Worcestershire, UK.
Posts: 4,241
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Re: Cheap multimeters
I have a Fluke 25. It's a big old beast - ex-MOD, as they mostly seem to be. I admit that because of the size, I rarely use it. It pre-dates the CAT-rating system, but it'll still be a rugged, safe meter.
Apart from safety, the AN8002 or AN8008 beats it on functionality and voltage resolution (the AN8008 does 1uV; the Fluke 25 does 100uV). On uA, they both do 10nA. The Fluke doesn't have a frequency counter, can't do capacitance, isn't true-RMS and doesn't have a backlight. It's only 3999-count. I know nothing of the GW 8145. Personally, I don't use my bench multimeters all that much, finding hand-held types much more convenient. But that's a personal preference thing. In general, bench multimeters aren't designed to have high CAT ratings like hand-held multimeters, as they aren't intended to be dragged around the switchroom; instead they are designed with much greater precision than a typical hand-held. That said, there is a "crossover" breed of bench multimeters that use hand-held multimeter chipsets, so relatively pedestrian precision (the GW appears to be one of those). Unless you really fancy a bench multimeter, it might be better on balance to go hand-held... Personally, I'd be tempted to go for the Fluke 25. Make sure the fuses are good - and the correct type are fitted - as replacing those could easily cost what you paid for the meter. And if you find you need more precision and more functionality, consider picking up the AN8002 or AN8008. That combination covers you for many applications, including those that might require a higher level of safety. I often need 2 meters at once, and occasionally 3. A few weeks back I was simultaneously monitoring 5 rails in that HP1740A 'scope that you helped me with! You can never have enough multimeters All the best, Mark |
15th Jul 2017, 7:05 pm | #40 | |
Dekatron
Join Date: Sep 2010
Location: Cheltenham, Gloucestershire, UK.
Posts: 3,077
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Re: Cheap multimeters
Quote:
The cheapo terminals are a bit of a let down but I suppose it's because of the price. The gaps in the uA to mA ranges are a concern too. But another meter could be used here instead? To use Dave's terminology, the Eevblog DMM looks like another 'cheap arse' meter to me but with extra safety features. A bit like putting lots of safety features on a cheap car. Every time you start it up you are still driving a cheap car every day with cheap performance and the benefit will only be gained if you do something daft with it
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Regards, Jeremy G0HZU Last edited by G0HZU_JMR; 15th Jul 2017 at 7:34 pm. |
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