Topic | 1.4 Ohms with probes shorted

Home Forums Mooshimeter Support 1.4 Ohms with probes shorted

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    • #14048 Reply
      nophead
      Guest

      When the probes are shorted together on the resistance I get a reading of about 1.4 Ohm. The leads have nowhere near that resistance, so why does it read so high?

    • #14050 Reply
      Anonymous
      Guest

      https://moosh.im/mooshimeter/specs/

      Resistance:
      Better than 1% accuracy over 20 Ohms – 20 Megaohms

      (Damn, we dont have preview to test what any of those tags do, so i have no idea what that “blockquote” does. Hopefully its readable :D )

      So, it basically says in the specs, that mooshimeter is only meant for resistances over 20 ohms.

      I’m planning to make some kind of higher current device to measure small resistances with mooshimeter, but that would need to have its own (variable) powersource and (variable) load to work.. And “free math” channel to show nice live values. If i ever get to a point where i really have it working, i probably write something about it here..

      And i thought that i have seen that name “nophead” and that profile-picture before.. 3d-printer was the magic word. I have orca ~0.30 and need more free time to play with it :D

    • #14051 Reply
      Anonymous
      Guest

      @James

      So, that blockquote did not do even close to what i was hoping, i dont mind if you clean that mess somehow..

    • #14056 Reply
      admin
      Keymaster

      Hi nophead and ville,

      nophead: Ville pointed to the correct spec, the Mooshimeter’s resistance measurement at the low end has a little bit of offset, which is why the accuracy rating only extends from 20Ω upward. The extra resistance you are seeing is a PTC thermistor – a circuit protection element that protects the resistance measurement circuit from overload. This element’s resistance is somewhat temperature dependent. If you hold the probes together and zero your measurement before you measure the next resistance you should see the offset disappear.

      Hope this helps, best
      ~James


      @ville
      : Thanks again for helping others in the forum. If you want to reach me though, my username is @admin :)

    • #14066 Reply
      Anonymous
      Guest

      Hi James,
      Yes using the zero button allows me to measure 1 Ohm reasonably accurately but it only works with the range locked. On auto range the zero value disappears when I disconnect the probes as it switches to the high range. When I attach the 1 Ohm resistor it goes back to the low range, the zero value re-appears, but it doesn’t get subtracted. So I think there is a small bug there.

      Also it is a bit odd that with the probes open circuit it shows something like 1.5K on the low range. When auto ranging it shows out of range as I would expect.

    • #14068 Reply
      admin
      Keymaster

      Thanks for pointing out that the issue with the app not displaying “out of range” in the lowest resistance range. The decision of whether to display the reading or “out of range” is made on the app side, not by the meter, so this is an app bug and I’ll make sure it gets fixed soon.

      Glad your measurements are otherwise good. Thank you!
      ~James

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