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  • EEVblog #99 – $100 Multimeter Shootout – Extech Amprobe BK Precision Ideal UEi Uni-T PART 1of2

    Posted on July 11th, 2010 EEVblog 22 comments

    PART 1 of 2
    Dave compares six $100 Multimeters:

    BK Precision BK2709B
    http://www.tequipment.net/BK2709B.html
    Extech EX505
    http://www.tequipment.net/ExtechEX505.asp
    Amprobe 34XR-A
    http://www.tequipment.net/Amprobe34XR-A.html
    UEi DM391
    http://www.tequipment.net/UEiDM391.html
    IDEAL 61-342
    http://www.tequipment.net/Ideal61-342.asp
    UNI-T UT61D
    http://www.uni-trend.com/UT61D.html


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    • http://www.toddfun.com/ Todd Harrison

      I couldn’t wait to watch the 100$ shootout so I watched it on YouTube before it posted at EEVBlog. I could tell this one was the hardest for you to film, edit and publish. It must have been rough. Well here’s to you Dave: Hip-Hip Cheers! Hip-Hip Cheers! And a big “Thanks you”.

      Todd

    • http://thexmoschallenge.wordpress.com/ Berni

      Nice review there!

      And i have to agree on the BK precision one. If only the thing wouldn’t beep so much! The UNI-T is quite a good choice too considering how cheep it is for all the features.

      • http://www.eevblog.com EEVblog

        If only the thing wouldn

        • http://thexmoschallenge.wordpress.com/ Berni

          Well all of these meters have there pros and cons. But the beep on the Amprobe god its almost torture to listen to it! I wouldn’t buy that meter just because of that sound it makes.(I bet some idiot put some sort of cap in the beeper oscillator, thinking it made it sound better)

    • ac

      That particular UNI-T model is just 40 EUR or 50$ *shipped* from china in ebay. I doubt the others are available such cheaply there.

      They have a higher end model that is ~$100 with shipping but given the quality of the internals shown here and the chance it is “slow” like the one here I wouldn’t go for it without similar indepth review, so overall the best decision is probably to save for a Fluke or go with the cheapest thing that has what one needs.

    • Sam Freedom

      Hey Dave,

      great job on the review. sadly i had to run my grandmother to the hospital for a couple of hours half way through the first video but i got back and finished it up about 12:00 am here my time.

      i do have a few questions though….

      1) what does the shunt affect in measuring things?

      2) i know that the meters have different cap ranges. what should be the lowest and highest possible range needed for an electronics hobbiest that is just starting out and is only dealing with DC applications?

      3) With the Extech EX505 showing some bad component lay out and such and there was a few shoots of the more expensive EX530 in the forums, does this mean Extech is not the well made products we had come to believe?

      4)i know the BK was able to light the LED which is great bc i think the spec is 3.5 test volt, but it doesnt show on the screen. how big of a problem is that for someone like me? i mean is it really needed or does it serve a serious purpose?

      thanks and again great job.

      • Edd

        Dave will probably come in and give you better answers, but I can help you out in the meantime:

        1) The current shunt is a low value resistor, such as 0.01ohms that goes in series with the circuit you wish to test current through. Using Ohm’s law, you can calculate current by measuring the voltage drop across the shunt. In an ideal world, you want the current shunt to be 0 ohms, but then there would be no voltage drop and hence no way to measure it. Dave made a project with much lower resistance current shunts to increase accuracy. Note that the lower the resistance of the load, the lower the resistance your current shunt must be, or you will greatly change the circuit and accuracy of your measurement.

        2) For cap ranges, lower is better. It’s not like you need to be measuring large electrolytics (as they are usually labelled). You want something that ideally goes down to a few pF, so that you can pick up any random ceramic or poly cap and measure it. 10pF to 10nF is good, 1pF to 100nF is great. Anything better than 10% accuracy is fine for a hobbiest and generally acceptable without buying a quality LC meter)

        3) -

        4) If it doesn’t display on the screen, then the only thing you can know about the LED is the polarity, not the forward voltage. It really depends on what you are doing. It’s not a problem for me, because if I was doing something serious with an LED, I would have a specific part with a datasheet, and just use the DMM to check polarity. For any other LED I find (bread and butter red/greens), I would probably just add resistance to get it to draw about 20mA and call it a day.

      • http://www.eevblog.com EEVblog

        1) what does the shunt affect in measuring things?

        It’s creates “burden voltage” when measuring current. See the full article:
        http://www.alternatezone.com/electronics/ucurrent/

        2) i know that the meters have different cap ranges. what should be the lowest and highest possible range needed for an electronics hobbiest that is just starting out and is only dealing with DC applications?

        Depends on what you generally work on, but in my opinion a lower cap range is more valuable than a higher cap range. 1pF resolution can be a handy thing to have.

        3) With the Extech EX505 showing some bad component lay out and such and there was a few shoots of the more expensive EX530 in the forums, does this mean Extech is not the well made products we had come to believe

        Their build quality is generally quite reasonable. You have to take each product on a case-by-case basis. Design and Layout is big aspect of this too, the EX505 is a good example of a very poor layout that manifests itself into a perceptible lack of quality.

        4)i know the BK was able to light the LED which is great bc i think the spec is 3.5 test volt, but it doesnt show on the screen. how big of a problem is that for someone like me? i mean is it really needed or does it serve a serious purpose?

        Not getting an actual reading is not really important, but the fact that it lights up a white LED is, so you can check the polarity before soldering or connection. The voltage drop of a LED will change with the current through it. So given that a meter only puts out a nominally low current like <1mA, the voltage drop at that current doesn't really tell you much on it's own.
        If the meter could put out selectable high level test currents, then the voltage drop would be really nice to know.

        Dave.

        • Sam Freedom

          thanks dave for answering my questions. i just have two more in response to your answers.

          1) is burden voltage something to worry about for a beginner in electronic hobby and is only dealing with simple DC applications?

          and

          2) does the BK’s cap range fit what you answered in the second question?

          • http://www.eevblog.com EEVblog

            1) is burden voltage something to worry about for a beginner in electronic hobby and is only dealing with simple DC applications?

            Generally not. But that depends entirely on the application. Most people simply “make do” by increasing the current range to lower the burden voltage.
            Many will simply live oblivious to what burden voltage actually is.
            Basically, if you don’t know how it’s going to effect you in the stuff you work on, then don’t worry about it when you come to buy a meter.

            2) does the BK

    • Michael Thompson

      I always enjoy this blog, however it seems that Extech gets a lot of good comments despite having one product after another have SOME kind of problem!
      It looks to me like they are inconsistent at best despite having good specs and SOME good qualities, but overall not worthy of the praise you give them.

      • http://www.eevblog.com EEVblog

        I always enjoy this blog, however it seems that Extech gets a lot of good comments despite having one product after another have SOME kind of problem!
        It looks to me like they are inconsistent at best despite having good specs and SOME good qualities, but overall not worthy of the praise you give them.

        I like to think I give both praise and criticism where it’s warranted, and take each meter and issue on a case-by-case basis.
        If you want a quality meter, you have to pay a lot more for the likes of a Fluke or Gossen, but even those meters have issues too! I could point out several downsides to the famous Fluke 87V for example. And I could rant on about the infamous Fluke 19.
        Extech’s EX330 that won the $50 shootout is a nice little meter for example.

    • Bearman

      Dave

      I applaud your efforts. This was a great shootout! I sincerely appreciate all your time invested on this topic. I for one think it is great work.

      Thank you again for a fine job well done.

      I was sorry to hear that the Extech does not work with LEDs. Until I saw your blogs I didn’t know that any meters had this LED lightup and forward voltage measurement capability built in. This would be a huge time saver. I usually have to breadboard a test circuit and test LEDs manually. I really want this feature on my next DMM.

      More and more I think I will just save up for the Fluke 87 V.

      Bearman.

      • Dan

        For the LEDs, I built one of these years ago: http://www.robotroom.com/LEDTester.html. Mine uses a two way female header socket, which is only good for leaded LEDs. I only ever use 3mm, 5mm, 0805, and 1206 LEDs. The LEDs always have markings on them, and I use this for checking colour when I mix them up.

    • John Pattillo

      Dave, Fantastic review. I think your efforts will have a positive effect on build quality from the companies (like Extech) who seem to want to listen. One thing I noticed was that there seemed to be a solder bridge across a couple of the pins on the main processor of the BK precision meter. Must not have been important pins.

      John

    • Steven

      That ideal meter is a piece of garbage. Jaycar market that brand as being as good as fluke. I’m not surprised it’s about as good as any other meter they sell there.

    • Shawn01

      Was I the only one who saw a solder short on the bk precision’s Main IC (top left corner in the video) or was that just some light pollution that caught my eyes off gaurd?

      If It was a short I could not figure out why Dave neglected to mention it. Although the bk was my favorite the need to watch their SMT line better.

    • vk6zgo

      A few years back,I worked at a place where

      they bought a number of UNI-T meters.
      (I think they were similar to the one tested)

      They had some annoying habits:-

      After applying the probes to do a test, the

      thing took so long to give a reading,that if

      we were looking for something that was only

      present for several seconds,it would miss it.

      For instance,if you were checking a cable for

      continuity,it was necessary to slow down your

      testing so the meter could keep up!

      Another beaut trick was how the resistance

      range became inaccurate when the battery

      started to fail(Before any indication of batt low on the display).

      Finally, the thing would turn itself off in

      the middle of a measurement!

      What is it with these modern DMMS? Even the

      new Flukes do this! ( Although you can turn it off)

      My old Fluke 77 will turn off if it isn’t

      measuring anything,but not in the middle of a

      reading!

      While I was thinking about this,I dragged my

      77 out,only to discover it isn’t working on

      the ohms range–bummer! I hope I don’t have

      to replace it with some cheap crud!

      VK6ZGO

    • Vinnie

      Does anyone know why the BK2709B displayed the word “Hold” when it turned on, but it doesn’t have a hold feature?

    • Geoff

      The ‘Extech EX505′ is really an OEM meter with custom colours, have a look at the ‘IP67 True RMS Autoranging Cat IV DMM’ in Jaycar’s catalogue (Cat: QM-1549). It is the same unit, and cheaper to boot.

    • http://orionrobots.co.uk danny

      I want that T-shirt slogan on a mug! I love Dave’s Tees…

    • Patrick

      Thanks dave for the informative review.

      I’m interested in buying the BK, but I really hate that it beeps each time you change the mood. Is there anyway to mute it? Or should I just solder a resistor to lower the beep noise?