Teardown: Amprobe AM-270 Digital Multimeter - Page 1
Forum section: electronics / testgear

author: FenderBender
author_rank: Super Contributor
timestamp: October 30, 2011, 10:36:24 pm
content: Here's another,Bought this thing for $90. I'm quite pleased for the price. Tons of functionality and very good build quality. Pictures:

author: FenderBender
author_rank: Super Contributor
timestamp: October 30, 2011, 10:37:56 pm
content: More

author: FenderBender
author_rank: Super Contributor
timestamp: November 08, 2011, 09:42:53 pm
content: I though I'd do a quick review also. More like some quick notes.Pros:-Pretty much every function you could dream of in a DMM-Rated accuracy is on par or better than many meters in it's price range-Separate mA/uA jack-High Quality Internal construction:+Huge HRC fuses+Routed isolation slots/plastic blast shields+Lots of input protection (vertical resistors even have their leads heatshrunk)+Nicel VReference Resistor 0.1%+O-Rings on screwholes and in input jacks+Overall high quality passives and construction+High quality soldering. No residue or junk+Intriguing range selector switch...-Appealing professional aesthetics-Audible jack alert. ie. Plugged in for current, but on voltage mode-Excellent price-pointCons:-LCD Backlight is blotchy: no light diffuser-"Kickstand" is a tad bit flimsy-Range switch is a little too stubborn for my taste, not very satisfying-No dedicated battery holder, just a compartment with a 9V battery clip on a wire.-Scratchy continuity tester. It's quick, but irritating.

author: Lightages
author_rank: Unknown
timestamp: November 09, 2011, 03:35:19 am
content: I am sorry but I meant to reply earlier. This looks like a very good buy and I somehow overlooked it earlier. Thanks for the information.

author: FenderBender
author_rank: Super Contributor
timestamp: November 09, 2011, 10:06:08 pm
content: Quote from: Lightages on November 09, 2011, 03:35:19 amI think you can hardly beat it for the price.

author: amspire
author_rank: Super Contributor
timestamp: November 09, 2011, 10:34:30 pm
content: It does look a great multimeter for the price.The one negative I could see is for current ranges of 500mA and below, it has a strangely high burden voltage.From the Amprobe data sheet, the burden voltage is 1.65V full scale on the 500mA range and 0.75V on the 5mA range full scale.On the 5A range however, you can resolve down to 1mA, and 500mA of current would cause a 15mV burden current and so most of the time, you could live with using the 5A range for measuring power supply current.Richard.

author: FenderBender
author_rank: Super Contributor
timestamp: November 09, 2011, 11:38:10 pm
content: Hmm...Well I don't think it was designed particularly for low voltages. More industrial wiring kind of stuff.I don't have a scope so I don't know if would really have an effect.Maybe I should get a uCurrent!

author: IanB
author_rank: Super Contributor
timestamp: November 10, 2011, 03:19:00 am
content: Quote from: amspire on November 09, 2011, 10:34:30 pmIt's not strangely high as in uniquely or oddly high, it is consistent with more or less every meter out there in any price bracket.Testing a whole range of my meters gives a meter resistance of 2-3 ohms on mA ranges and 100 ohms on uA ranges. I was surprised at the consistency of these measurements. I meaneverymeter was about exactly 100 ohms on the 200/400/500 uA range.

author: PeteH
author_rank: Unknown
timestamp: November 10, 2011, 04:43:46 am
content: I'm curious, does this meter give audible warning if you switch to measure voltage and forgot to change the probe over?

author: FenderBender
author_rank: Super Contributor
timestamp: November 10, 2011, 03:50:04 pm
content: Quote from: PeteH on November 10, 2011, 04:43:46 amYes it does.

author: PeteH
author_rank: Unknown
timestamp: November 10, 2011, 03:55:33 pm
content: I could see the split input jacks, usually the usual method for detecting the probe. Looks like a good meter!

author: FenderBender
author_rank: Super Contributor
timestamp: November 10, 2011, 06:10:19 pm
content: Wow you have some sharp eyes. I didn't even notice they were split jacks. Haha. Atleast there the good quality split jack type.

author: sorin
author_rank: Frequent Contributor
timestamp: November 27, 2012, 10:34:52 am
content: just 5000 counts

author: FenderBender
author_rank: Super Contributor
timestamp: November 27, 2012, 01:26:01 pm
content: Is that bad?

author: Salas
author_rank: Frequent Contributor
timestamp: November 27, 2012, 01:38:19 pm
content: Looks like it was designed with electricians in mind. Much input protection, hard switch for hand in industrial glove, so so tilting bail because almost always on hand or hanging off a terminal's frame, waist clip, 5000 count to have the important stuff in big size.

author: Lightages
author_rank: Unknown
timestamp: November 27, 2012, 01:54:35 pm
content: It may have been designed for electricians, but it has all the right stuff for almost any electronics work. 5000 count? So it isn't 40000, big deal. For the price it is a bargain and safe for newcomers to the hobby/profession.

author: peter.mitchell
author_rank: Super Contributor
timestamp: November 27, 2012, 02:10:45 pm
content: 5000 count is amazing, 4000 count sucks big ones (not the aerosmith album either), 5000 means you can see the voltage on a lithium chemistry battery in high resolution, 4000 not so much

author: multiJ
author_rank: Contributor
timestamp: November 27, 2012, 08:59:04 pm
content: It would have been great if AM-270 was available for sale in Europe

author: StubbornGreek
author_rank: Frequent Contributor
timestamp: November 27, 2012, 10:21:35 pm
content: I was considering picking up an AM-140. This little review instills some confidence...hmmThanks for your input.

author: dr_p
author_rank: Frequent Contributor
timestamp: November 27, 2012, 10:42:30 pm
content: Quote from: multiJ on November 27, 2012, 08:59:04 pmI live in Europe and got it for 90$+35$ shipping fromTequipement.net. It took 10 days more or less, half of that before departing the shop.

author: Lightages
author_rank: Unknown
timestamp: November 28, 2012, 02:06:15 am
content: Quote from: StubbornGreek on November 27, 2012, 10:21:35 pmHave a look at this too.https://www.eevblog.com/forum/product-reviews-photos-and-discussion/amprobe-am-140-a/msg155623/#msg155623

author: iloveelectronics
author_rank: Frequent Contributor
timestamp: November 28, 2012, 02:35:49 am
content: While we are on the topic of these Amprobe meters which I believe are basically Brymen's inside a different housing and badge, I have just got myself a Brymen BM-257. I will post some pictures and perhaps a short review if anyone's interested.http://www.brymen.com.tw/product-html/cata250/Bm250s.htm

author: T4P
author_rank: Super Contributor
timestamp: November 28, 2012, 05:25:01 am
content: Quote from: iloveelectronics on November 28, 2012, 02:35:49 amPlease do

author: retiredcaps
author_rank: Super Contributor
timestamp: November 28, 2012, 07:20:08 am
content: Quote from: iloveelectronics on November 28, 2012, 02:35:49 amYes, please!!!

author: StubbornGreek
author_rank: Frequent Contributor
timestamp: November 28, 2012, 09:43:37 am
content: Quote from: Lightages on November 28, 2012, 02:06:15 amThanks. I saw those but didn't realize he was on this forum.

author: multiJ
author_rank: Contributor
timestamp: November 28, 2012, 09:53:49 am
content: I contacted them (tequipment) a couple of weeks ago and they said they have "a minimum $300.00 international order requirement". Go figureQuote from: dr_p on November 27, 2012, 10:42:30 pm

author: dr_p
author_rank: Frequent Contributor
timestamp: November 28, 2012, 05:36:14 pm
content: Quote from: multiJ on November 28, 2012, 09:53:49 amI just went ahead and placed the order, payed by Paypal and it all went smooth. While watching the video and pictures on their site I noticed that there is also an AM-270without bar-graph, so I confronted them and they ensured me it has the bar-graph version. It was well packed, and I'm very happy with it.

author: multiJ
author_rank: Contributor
timestamp: November 28, 2012, 06:27:35 pm
content: Thank you very much for the heads up, I will check this outQuote from: dr_p on November 28, 2012, 05:36:14 pm

author: FenderBender
author_rank: Super Contributor
timestamp: November 29, 2012, 12:07:52 am
content: It's called an AM-250. All AM-270s have bargraphs.

author: multiJ
author_rank: Contributor
timestamp: November 29, 2012, 10:29:39 pm
content: Would love some pictures and short review too, to compare this with Amprobe DMMsQuote from: retiredcaps on November 28, 2012, 07:20:08 am

author: dr_p
author_rank: Frequent Contributor
timestamp: November 30, 2012, 08:59:08 am
content: Quote from: FenderBender on November 29, 2012, 12:07:52 amThis video is fromtequipement's site: notice the lack of 4 buttons and bargraphAnd it says AM-270 TRMS on the meter!!

author: retiredcaps
author_rank: Super Contributor
timestamp: November 30, 2012, 09:13:47 am
content: The same video is on amprobe's websitehttp://content.amprobe.com/video-dmm/Amprobe%20CAT%20IV%20Digital%20Multimeter.htmlbut the high definition pictures says "w/Bar-graph Display"http://content.amprobe.com/HighResImages/am-270.jpg

author: iloveelectronics
author_rank: Frequent Contributor
timestamp: November 30, 2012, 09:23:44 am
content: Quote from: retiredcaps on November 30, 2012, 09:13:47 amThey don't even look like the same meter. One has 8 soft buttons while the other only has 4! Confusing...

author: cybergibbons
author_rank: Frequent Contributor
timestamp: December 01, 2012, 09:00:09 pm
content: Quote from: dr_p on November 27, 2012, 10:42:30 pmPretty much my experience as well, though I got raped on customs charges.

author: dr_p
author_rank: Frequent Contributor
timestamp: January 04, 2013, 02:21:03 pm
content: Ok, been using this for some time and I've got things to tell you:To silence the beeps when pushing buttons, one can holdHzbutton while powering on via rotary selector. When the meter enters auto power off, one can wake it up by pressing any button, not just theselectbutton like the manual says. But surprise-surprise, the beep is now ON, so I'm forced to rotate the selector to OFF, then desired range again while holdingHz(the usual way).Now I accidentally found that if you wake it up from auto power off by HOLDING the Hz button, meter says "dsbld" or whatever it usually says (e.g. disabled beep) and beep is still OFF.Hope it helps some people. Funny fact: I was so happy I found this out and my sleeping GF won't be bothered by the beeps that I reverse mounted an electrolytic cap (100uF, 50V connected to 27V). It was like 1:00 AM and I was troubleshooting some analog stuff. 40 seconds later I smelled something heating up and glanced at myMAVO35just to see it at 10mA and then violently shoot to full scale(100mA). I touched my 2 ICs but thy were ok, then I spotted the cap bulging in my face. I mean like 20cm away. First thing that went through my head was UNPLUG THE SCOPE, I JUST BOUGHT IT!!!Don't look for any logic in that, it's not like it will ever get electrically damaged by a bursting cap. I managed to unplug it and just started turning my head away when it exploded in (almost) my face. I'm totally fine, thank you. %-BThe moral is: leave the beep on, it saves you from caps exploding in your face.

author: jhufford
author_rank: Contributor
timestamp: May 17, 2015, 07:56:32 pm
content: So after a few years of using this meter, any final verdict? Is it suitable for general electronics work or only for electricians? From the specs it looks pretty good for electronics work. It has a 50mV and 50 Ohm and 500uA range and quick continuity tester...I'm comparing it to the BK2970B or 2712 . But the BK doesn't have temperature and its beeping when turning the switch is darn near a deal breaker. Duty cycle is about the only thing missing from the 270 and it's frequency bw is only 125k but good enough for quite a few of the switching circuits I do, I can use the scope for anything higher than that.I tend to do an odd smattering of projects, from battery power microcontrollers to high-voltage with flyback transformers. I thought the the am-270 might suit nicely and be a nice replacement for my <$50 ideal meter. (or might the BK and a separate temperature meter be best?)Thoughts anyone?

author: Lightages
author_rank: Unknown
timestamp: May 17, 2015, 08:36:08 pm
content: It was a great buy when it was only $90. Now it is $105 so not quite as nice a deal but still good. I would still recommend it for anyone who needs a well built, safe, and accurate meter for around $100. I don't have one but it is the same as a Brymen BM815. I haven't heard anyone complain about the 270 except for the bad back light.

author: dr_p
author_rank: Frequent Contributor
timestamp: January 11, 2016, 08:59:07 pm
content: I did a backlight mod today - replaced all 4 LEDs with high efficiencyredones. Whites would not even light up, as voltage before the resistors seems to be 2.4V. I couldn't be bothered to research more, so I just put the red ones in and they are clearly more bright than the stock green. Also added 3 layers of matte film from a broken LCD screen. The one that looks like sandblasted glass. I tried to space them referenced to each other, as to maximize the light dissipation.For reference, stock backlight is very bad, similar if not identical to this Brymen:https://pbs.twimg.com/media/BCiSbY8CMAAGMDZ.jpgI also added some pictures with the areas that the OP missed - main chipset and the back side of the PCB.

author: Johnny Electron
author_rank: Contributor
timestamp: August 25, 2016, 04:49:42 am
content: Just to add info for new buyers which may be searching these old threads, the backlight is now fixed! It is now a nice orange like the brymen meters when the 's' was added to their model numbers.

author: AndyBollo
author_rank: Newbie
timestamp: November 30, 2017, 07:21:08 pm
content: Hello!I bought the AM-270 on Dec'2013 and it already came with the nice orange backlight. Almost 4 year now and I still very happy with the purchase, is a very useful and good equipment. Perfect for electronics repair. DIYers should no look further.

author: osteichthyes
author_rank: Contributor
timestamp: August 15, 2018, 09:26:41 am
content: I don't mean to resurrect an old thread, but I've been using one of these for about a year and I absolutely love it. I was recently offered a sweet deal on a Fluke 87 and realized that aside from its great form factor and nice feeling in the hand, it really didn't do much my 270 doesn't. And the Amprobe does a lot the (original) 87 doesn't. All that is to say, it's a heck of a meter! (I don't mean to suggest that a comparison of products made 20+ years apart is reasonable, but rather that it does a lot of things really well).I did notice one oddity when I took it apart recently. Around the input jacks, there's a piece of plastic that runs in the slit in the board. On my AM270, the battery wire ran underneath this plastic and actually got pinched a bit. So, I took the board out and ran the wire around it. This meant the battery wires run directly on top of the 10A input jack. Which, I'm sure is fine, but it seems like a surprising design oversight. Anyone else have any thoughts about this?