Advice on buying a Multimeter

Discussion in 'General Electronics Chat' started by raziiq, Nov 25, 2009.

  1. raziiq

    Thread Starter Active Member

    Dec 15, 2008
    Hi there.

    I am new to electronics world and within 2 weeks i came to know that i cant do anything in this Electronic World without a Multimeter.

    So i need advice on buying a NOT VERY EXPENSIVE multimeter for my projects.

    What should i keep in mind before buying a Multimeter?
  2. raziiq

    Thread Starter Active Member

    Dec 15, 2008
    BTW what about this Multimeter


    - Diode Measurement
    - Transistor Measurement
    - DCV (200mV, 2000mV,20V,200V,500V)
    - ACV (200V, 500V)
    - DCA (200μA, 2000μA, 20mA,200mA,10A)
    - Resistance (200Ω, 2000Ω 20kΩ,200kΩ,20MΩ)
  3. ntmarwade

    New Member

    Nov 3, 2009
    Yes, Multimeter is very much important while analyzing the circuits.

    Mostly it is used for

    1. Voltage measurements (AC/DC)
    2. Current Measurement (DC mAmp or Amp, very few meters can measure AC current RMS value)
    3. Resistance (upto megaohms), continuety with low resistance.
    4. Diode test

    The meter pricing varies as per following

    a. measurement resolution
    b. measurement range (lower/upper)
    c. Sensitivity
    d. Duarability
    e. Test approvals and Certifications
    f. Brand name

    be carefull about following while using meter

    1. correct parameters selection
    2. correct range selection
    3. correct polarity connection

  4. raziiq

    Thread Starter Active Member

    Dec 15, 2008
    So whats your say on the Multimeter i have posted above?
  5. Wendy


    Mar 24, 2008
    It looks OK, you can probably get cheaper with good results.

    I like having two of them, a cheap unit that I won't cry over if I do something stupid, and a better one with the extra bells and whistles, such as a freq counter and capacitance meter. The transistor beta tester is almost never used IMO.

    The cheap (really cheap) units are about as accurate as the good ones, until you fry them.
  6. KL7AJ

    Senior Member

    Nov 4, 2008
    This is surprisingly true! I got a bunch of $8 Chinese DMMs for my electronics class, and they're every bit as accurate as my high end Fluke. Except my Fluke has fallen off a few towers and been dropped in a bucket of linseed oil and still works. :)

  7. t06afre

    AAC Fanatic!

    May 11, 2009
    I do not know if it is important for you. But then it comes to AC the cheap ones is not good for anything over 200Hz (this may vary somewhat). But they will function OK for 50 and 60 Hz. But most of my AC measurement is mains related, say measuring a transformer output. So it is not very important. The function I use most besides voltage measurement, is the beep function. The instrument beep then the input is shorted.
  8. someonesdad

    Senior Member

    Jul 7, 2009
    You don't say where you're located, so this advice may not apply. If you're in the US, you can go to Harbor Freight and get their cheap DMMs for under $10 (our local store used to sell these for $4). These are an excellent value for the money and you don't get too upset if you run over it with your bulldozer. However, you have to understand that they're not lab quality instruments, so you should rightly suspect that the accuracy may not be equal to the more expensive meters.

    Get more than one -- I suggest at least two. The reason is it's common to want to simultaneously know both the current and the voltage in a circuit, so having two makes this easier to do.

    Later, after you gain experience, you can buy a more expensive meter when you have a better idea of the features you really need.

    Everyone's different, but here are the features that I must have in my digital multimeter:

    • Autoranging (and I like it to be speedy). If you make a lot of electrical measurements, having to switch ranges will eventually drive you crazy. That's why, personally, I would never buy a meter like the one show in the OP's picture.
    • Ability to select a specific range and keep it there (and I want the measurement time to be 0.1 s or less)
    • AC, DC voltage measurements to at least 500 V or so
    • A mV scale (resolving to 0.1 mV) for both AC and DC
    • Reasonable AC bandwidth -- say, accuracy within 0.5 to 1% over 40 Hz to 400 Hz
    • Diode measurement
    • Differential measurement mode (press a button and the current reading is subtracted from all subsequent readings)
    • Audible beep for continuity checking. My ideal meter would allow me to set the frequency of the beep and the resistance below which the beep occurs.
    • A back light for the display
    • An AC and DC μA scale resolving to 0.1 μA
    • At least 10 MΩ input impedance on all voltage measurements
    • Protection against damaging voltages of at least 600 V on voltage and resistance measurements
    Here are features I consider nice but not mandatory (I can do all these at my bench or drag a scope to where I'm working if I have to):

    • Averaging, max, and min measurements
    • Frequency measurements
    • RMS measurements
    The one thing I would change if I could about my current DMM is to have it use cheap AGC glass fuses on the current ranges, rather than the expensive ($5-$10 each) fast blow fuses. I have an HP 3435 bench meter that I bought over 30 years ago that does precisely this and it is very handy, especially when one measures current a lot.

    I also don't need high accuracy -- 0.5% to 1% is fine for most measurements. If higher accuracy comes with the meter, I won't complain, but the above features are far more important to me than accuracy. If I need accuracy, I use my bench equipment -- if I didn't have the more accurate bench equipment, then I'd probably demand more accuracy in my DMM.
  9. KL7AJ

    Senior Member

    Nov 4, 2008
    One other thing that I find absolutely crucial (which may be of lesser importance to the OP) is some sort of ANALOG indicator. My Fluke has a little bar graph which is extremely useful. In most of what I do in R.F. electronics, I'm looking for a PEAK or a DIP in some value....being able to determine this quickly is far more important than digital accuracy! It's really hard to look at rapidly changing numbers on a digital display and figure out if they're going up or down!

  10. raziiq

    Thread Starter Active Member

    Dec 15, 2008
    Thanks for all the suggestions, infact i am very new to this stuff , so going for this cheap one at first. I am in Japan and the one i posted is almost $10.