I am trying to measure new electrolytic capacitors before they go into my guitar amp to make sure that they are up to spec. I'm using a Morris #57044 multimeter, which has an autoranging capacitance measurement setting.

I've used it to test a couple of capacitors, all in the microfarad range (20 - 150 uF), and each time, the meter stays at 0 for a bit, shows a reading in nanofarads, then registers overload OL. The meter is supposed to have a range from 10pF - 200uF. EDIT: Looking more closely at the spec sheet, I see the meter has 40nF as its lowest range and 200uF as its highest range. This should still read a 100uF cap fine though, if I understand correctly.

I am discharging my capacitors before measuring, making sure I am using the leads on the right sides of the cap, and using the relative REL button on the multimeter to zero out internal capacitance of the leads (though the problem persists even when I don't do this).

Is my meter not working properly? Am I doing something wrong?

Product page: https://www.morrisproducts.com/pc_product_detail.asp?key=B22E69AD80464A1584F58EF688EE7E38

Spec sheet: https://www.morrisproducts.com/images/57044-specsheet.pdf

Thank you in advance for your help!

  • \$\begingroup\$ Do all the other functions work okay? \$\endgroup\$ May 8 '20 at 1:16
  • \$\begingroup\$ Are you trying to measure capacitors while they are installed in a circuit??? Powered or not, you can't do that. \$\endgroup\$
    – Kyle B
    May 8 '20 at 4:38
  • \$\begingroup\$ All the other functions work well! And all of the capacitors are completely out of circuit, fresh from the packages they were shipped in. \$\endgroup\$ May 8 '20 at 7:19
  • \$\begingroup\$ It does sound then like your meter is whacked. There's no super-tricky thing you need to know to read caps as large as you describe. Tiny caps are a different story (nF stuff) I doubt you are having trouble with this, but note if you don't hold the probes tightly and for a period of time, the meter can't run it's test. "maybe" using clips instead of probes would help. \$\endgroup\$
    – Kyle B
    May 8 '20 at 19:25
  • \$\begingroup\$ Another possibility is that your caps actually ARE bigger than 200uF. You 'd be pretty surprised at the tolerances on electrolytic capacitors. Does the meter measure, say, a 10uF cap correctly??? If it can't do that, it's new meter time.... \$\endgroup\$
    – Kyle B
    May 8 '20 at 19:26

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