DMM continuity test

Discussion in 'General Electronics Chat' started by Marc0, Oct 14, 2012.

  1. Marc0

    Thread Starter Member

    Nov 28, 2011
    I was wondering about what's the max resistance value allowed between two points in a circuit, to say that there's continuity between them.
    This question arose while I was working with some SMD resistors (a few ohms) and noticed that my DMM was buzzing in continuity mode when testing some of those
  2. vk6zgo

    Active Member

    Jul 21, 2012
    Easy answer--- don't use your continuity mode to measure resistors.

    Seriously though,it is a problem if you are checking cables which may have high resistance connections.
    The readout will usually show a difference,even though the "beep" is the same.
    Of course,if you have to look at the display,why not just use the Ohms range?
  3. Marc0

    Thread Starter Member

    Nov 28, 2011
    Ok...but my question was more conceptual than practical.
    What resistance value is considered acceptable to say that 2 points are in continuity? Is there a standard?
  4. PackratKing

    Well-Known Member

    Jul 13, 2008
    Wouldn't it hinge on what was between those two points ?? :confused:
  5. Lundwall_Paul


    Oct 18, 2011
    Take your DMM to a decade box to hear when the tone comes on. I believe that I did this with a Fluke and if I remember correctly I heard the tone around 50 ohms.
    Marc0 likes this.
  6. Marc0

    Thread Starter Member

    Nov 28, 2011
    Did something similar with a variable DMM starts buzzing at about 30 ohms.
    Yesterday was testing a circuit, there was a smd resistor (5 Ohms) placed in series between the PSU and some opamps. The opamps weren't getting power so I started checking the circuit for continuity...checking that resistor there was no continuity, but didn't know if it was because of the too high resistance or because the resistor was blown.
    End of the story: the resistor was blown...for my DMM under 30 Ohm there is continuity, if the resistor is 5 Ohms and there's no continuity...well it's the resistor fault.
    throbscottle likes this.