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  • เผยแพร่เมื่อ 29 ต.ค. 2024
  • How Dave checks the "calibration" of the multimeters in his lab.
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ความคิดเห็น • 63

  • @arcadeuk
    @arcadeuk 12 ปีที่แล้ว +7

    Wow David, Can't believe your HP meter and the voltage reference were both accurate to 5 decimal places right out of the box. What excellent examples of high quality engineering they both must be

  • @EEVblog
    @EEVblog  12 ปีที่แล้ว +5

    Time and patience. It's MUCH harder being in Australia too, as shipping costs suck, and many don't ship here.

  • @EEVblog
    @EEVblog  12 ปีที่แล้ว +3

    That's ok, start cross-checking them and keeping a log to see if they drift. When you get a chance, compare one against a better meter and see how it shapes up.

  • @yoramstein
    @yoramstein 6 ปีที่แล้ว +19

    Nice introduction but where is the calibration process?

    • @mtkoslowski
      @mtkoslowski 5 ปีที่แล้ว +4

      Yoram Stein : thatwhat I was hoping for.

  • @bloomtom
    @bloomtom 12 ปีที่แล้ว +3

    Usually a precision Zener diode reference. Some labs use mercury/silver oxide/zinc air batteries as their voltage is extremely stable over the life of the battery.

  • @jessstuart7495
    @jessstuart7495 7 ปีที่แล้ว

    Quality people love calibration. The last electronics CM I worked for bought a few cheap DMM's for test technicians, then was paying double what the DMMs are worth each year just so they have a valid calibration certificate. Our quality manager had never seen or heard of a "No Calibration Required, Not to be Used For Conformance Testing" label before and thought everything always needed to be "in-calibration". Many calibration houses will not even tell you what they needed to do (if anything) to calibrate a meter, or how much the meter was off.

  • @ChrisWilson5006
    @ChrisWilson5006 12 ปีที่แล้ว

    Another excellent and useful video, thanks Dave!

  • @scottoma
    @scottoma 12 ปีที่แล้ว

    Thanks Dave, much appreciated.

  • @amiga8761
    @amiga8761 2 ปีที่แล้ว

    No data could be used for reports or documentation, However could still use the test equipment when calibration was not required. I would issue that type of test equipment when no precise testing measurement was required. Working at a calibration lab for the Navy.

  • @evilteddy11
    @evilteddy11 12 ปีที่แล้ว

    It used to be standard cells with a well defined cell potential. Nowadays I think that something called the Josephson effect is still used for standards. A Josephson junction is a superconducting junction that you can apply a DC voltage which will produce an oscillating current over the junction at a frequency dependent on the applied voltage. Luckily the reverse is also true. An applied AC current will produce a DC voltage which is dependent only on the frequency. Not the current magnitude.

  • @pault6533
    @pault6533 9 หลายเดือนก่อน

    Let’s say you have a standard that is accurate to 10.00000. Now you want to calibrate a DMM to 10.00. Should you (1) turn the adjusting potentiometer until the display is flickering between 9.99 and 10.00, or (2) turn the adjustment until there is a solid 10.00 on the display?

  • @ElectronicsPubVideos
    @ElectronicsPubVideos 12 ปีที่แล้ว +2

    Dave, what is calibration at all?! Does they trim some pots or some stuff to bring up meters to spot on, or they just tell you how much you are off from the actual value and you have to keep that in mind while using your stuff?! CMON DAVE!

  • @carnby24
    @carnby24 10 ปีที่แล้ว +6

    Hi, i have a fluke multimeter, and we sent them to be calibrated, but the lab returned the DMM with blown fuse, is this normal during calibration?

    • @floriandaler5327
      @floriandaler5327 6 ปีที่แล้ว +4

      Edward Carnby They checked if the fuse is still in its nominal specs :D

    • @camurgo
      @camurgo 6 ปีที่แล้ว

      Surely not.

  • @jenniferw8963
    @jenniferw8963 7 ปีที่แล้ว +2

    Have a question about the resistors. I see those ones you have in your calibration device you built cost like $15-25 a piece! WOW!
    I was wondering. Can't I just take a cheap penny 10k resistor down to my electronics shop and have him record the exact reading they get with their 6.5 digit meter, onto a piece of paper? Then when I make the little black box with handy connectors like you've done, I just write down the recorded reference value and compare meters to that number? Would save a lot of money that way at least.

    • @allesklarklaus147
      @allesklarklaus147 7 ปีที่แล้ว +2

      Nope, resistor can drift with time and will drift with temperature and humidity. You need at least a stable one to do this. If your electronics shop does this measurement for free you could give it a try with a low tempco, stable resistor but it will be in the couple of bucks range at least.

    • @GRBtutorials
      @GRBtutorials 7 ปีที่แล้ว

      Keep in mind that it'll last a lot of time and it's very high precision. If you want, you can buy a slightly worse one. You can use parametric search and order by price. And remember to check that the minimum quantity is 1! I would use Digikey since they have very good parametric search, and if the order is more than 50 €/$, you have free shipping! You can order two of those and have free shipping.

  • @ganopterygon
    @ganopterygon 4 ปีที่แล้ว

    well brand new DMMs are calibrated at factory yes but wierd things can happen, and happened to me one, I bought a 6 1/2 digit DMM for work with calibration certificate etc. and 4 months after that a calibration team came to the site to perform on-site calibration and I put this DMM on the list, they told me there was not need to calibrate because it was purchased 4 months ago, I of course insisted and yeah next day they were shocked that frequency measurement was off by ~50KHz in the 300KHz range, what could happend, something in the shipping? I don't know :)

  • @papalevies
    @papalevies 12 ปีที่แล้ว +3

    I've always wondered, isn't this a chicken and egg problem? Is there a standard to calibrate your standards to?

  • @EEVblog
    @EEVblog  12 ปีที่แล้ว +3

    Sorry, no idea how that would have been. I was just playing around with my DC standard the other day and thought I'd brag about the 1.00000 reading :->

    • @Fezz21
      @Fezz21 4 ปีที่แล้ว +1

      at least your honest bud lol

  • @kirillsh8383
    @kirillsh8383 4 ปีที่แล้ว +2

    which accuracy is needed for modern digital electronics?

    • @ArumesYT
      @ArumesYT 4 ปีที่แล้ว +2

      By its very nature digital doesn't require much accuracy at all. Analog is much more critical. For instance, when you use an IC at 2Vcc, a HIGH input signal can be anywhere from 1.5V to 2V. And LOW input is anywhere from 0V to 0.5V. (data taken from an NXP 74HC595 datasheet) So in order to check those signals you don't need any accuracy at all. For digital, being able to capture *sequences* of voltages is much more important. You'll find yourself switching to a logic analyzer and/or oscilloscope instead of a multimeter very quickly when you start working with digital signals.

    • @kirillsh8383
      @kirillsh8383 4 ปีที่แล้ว +1

      @@ArumesYT Yeah, I know. Just curious where it is needed in modern digital world. Rf design?

  • @juanolmosmendoza5361
    @juanolmosmendoza5361 2 ปีที่แล้ว

    question in some multimeter models there is no contonuity function and diode measurement it is possible to add this function as in the case of the multimeter HP3468A

  • @AlpineTheHusky
    @AlpineTheHusky ปีที่แล้ว +1

    10 years later any any kind of electronics gear is now expensive as hell

  • @rustyrebar9647
    @rustyrebar9647 5 ปีที่แล้ว +1

    So how do I calibrate my hp3478a? I was under the impression that you'd show us how it's done.....

    • @hightttech
      @hightttech 2 ปีที่แล้ว

      You need a pocket screwdriver to put it in CAL mode, shorting straps for front & rear terminals, and $$$ of AC, DC and Resistance standards. AC is the worst because "complete" CAL requires 280 VAC @ 100kHz, and 25VAC @ 300kHz ref 😆.

  • @ChristiaanLombard
    @ChristiaanLombard 12 ปีที่แล้ว +3

    At some point someone would have to manually count the electron flow :)

  • @123456789robbie
    @123456789robbie 12 ปีที่แล้ว +1

    the absolute accuracy doesn't matter because it can be compensated for by calibration, right?

  • @GeorgeGraves
    @GeorgeGraves 12 ปีที่แล้ว

    Nice! Dave is this the 2nd or 3rd video I've inspired? (or am I crazy?!?!?!?)

  • @conoba
    @conoba 12 ปีที่แล้ว +1

    Could it be that older high end references and multimeters are very stable because they are "burned in" by years of use?

  • @rng8891
    @rng8891 12 ปีที่แล้ว

    I found an article I had purchased from Silicon Chip talking about a 5V precision Reference using a Maxim MAX6350. I think I've seen similar articles elsewhere. I've always wanted to build one but never got around to it. What do you think? Could I use the MAX6325, MAX6350 as a poor hobbyist calibration standard?

  • @papalevies
    @papalevies 12 ปีที่แล้ว

    Thanks guy

  • @rainbowsalads
    @rainbowsalads 12 ปีที่แล้ว

    What natural reference does a calibration lab use for the industry standard ?

  • @EEVblog
    @EEVblog  12 ปีที่แล้ว

    This may indeed be my most costly video to date!

  • @CorbyStarletCj1
    @CorbyStarletCj1 12 ปีที่แล้ว +2

    That's it i'm off to calibrate my meters, Shit i don't have a DC voltage standard ........

  • @DLTX1007
    @DLTX1007 12 ปีที่แล้ว +2

    Wow the resistor is now 72bucks! My eyes hurts ...

  • @Stover159
    @Stover159 6 ปีที่แล้ว

    What’s the main difference in a 3468 and a 3478?

  • @BobElHat
    @BobElHat 12 ปีที่แล้ว +2

    They wanted it to go to 11 but their bosses wouldn't let them, so they made it so it would go up to ten point ten.

  • @HeartOfGermany
    @HeartOfGermany 12 ปีที่แล้ว

    That is very accuate. where do you actually need that? I mean, you have a wide Voltage tollerance on almost anything of at least over 1. Where does this actually come in handy?

  • @AlanGarfield
    @AlanGarfield 12 ปีที่แล้ว

    This video cost Dave a hot sweaty summer in his lab. ;)

  • @adfalmeida10
    @adfalmeida10 10 ปีที่แล้ว

    Hi, David, please let me know if you have an EDC MV-106 to sell or where I can to Find this! tank you by help!

  • @AlanGarfield
    @AlanGarfield 12 ปีที่แล้ว

    Easy, grey beard tongue angle! In nature nothing is more accurate.

  • @Crazytesseract
    @Crazytesseract 4 ปีที่แล้ว

    Can you measure 100 to 500 nano volts?

  • @rainbowsalads
    @rainbowsalads 12 ปีที่แล้ว

    thanks : )

  • @pikuorguk
    @pikuorguk 12 ปีที่แล้ว

    The way you can dial up "10.1010101010" using the knobs is messing with my head :)

  • @38911bytefree
    @38911bytefree 12 ปีที่แล้ว

    There are standards made just for check instruments ....

  • @kaybhee6
    @kaybhee6 3 ปีที่แล้ว

    need v ac ref... please

  • @DeKempster
    @DeKempster 12 ปีที่แล้ว

    I upgraded form a 10$ meter to a Agilent U1241B :D

  • @thehitman5007
    @thehitman5007 6 ปีที่แล้ว +2

    Yada yada yada, waste of my 14.31 minutes and still no shit been done. Thanks mr show off.

  • @BeerTower
    @BeerTower 12 ปีที่แล้ว

    Josephson junction

  • @WickedEngineer
    @WickedEngineer 12 ปีที่แล้ว

    i got a wavetek datron 9000 on sale, anyone interested ?

  • @foxyrollouts
    @foxyrollouts 8 ปีที่แล้ว

    Id call the unit a secondary std

  • @lb5sh
    @lb5sh 12 ปีที่แล้ว

    Watching that reversed Z is like growth hormones for my OCD.

  • @supermanreturns3659
    @supermanreturns3659 6 ปีที่แล้ว +2

    blah blah blah ...and the calibration process ?

  • @BIgGuidojoe
    @BIgGuidojoe 12 ปีที่แล้ว

    pshh, fluke 45 bench meter all the way dave!

  • @dealio82
    @dealio82 12 ปีที่แล้ว

    first