Inaccurate Multimeter Readings

Discussion in 'General Electronics Chat' started by Scott216, Feb 25, 2013.

  1. Scott216

    Thread Starter New Member

    Jun 16, 2011
    I have an Extech MN35 multimeter. This is a small inexpensive meter. Recently I tried to measure the current going from a solar panel to a small motor. The solar panel only puts out about 3 volts and the motor draws less then 1/2 amp. With this meter I tried measuring both voltage across the motor and the current going to the motor. But reading were erratic. So I tried my more expensive Fluke meter and it worked fine. A also recently tried to measure the current going to a 115 volt blower which I draws around 2 amps. This didn't work either on the Extech MN35. I'm guessing this meter is affected by noise in the line that the motor creates, but I'm not sure. Anyone have some theories as to why this meter doesn't work in these conditions? Is there some sort of spec I should look for on the data sheet that would tell me if a meter has this kind of limitation?
    I'd really like to find a small good quality multimeter, but most of the small ones seem to be low-end.
  2. Jaguarjoe

    Active Member

    Apr 7, 2010
    If you already have a Fluke, what more could you want?

    I have 3 or 4 Harbor Fright cheapos strategically placed around the house and car. For non critical measurements they're fine. If I drop one off the ladder I'm only out 5 or 6 bux.
    I save my Fluke for accurate measurements. If I broke it I'd have a hard time replacing it.
  3. Neosec


    Feb 25, 2013
    Does the Extech measure a battery's voltage ok? Like 1.5 volt AA? or 9 volt? No motor noise there. I'm thinking maybe a blown fuse in the meter though that usually means no measurement at all, not an erratic one.
  4. Scott216

    Thread Starter New Member

    Jun 16, 2011
    The meter works fine for measuring batteries.