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I'm just a hobbyist but I like to purchase quality tools so I purchased an "only used once" Fluke 87V on eBay. The calibration sticker says the calibration expired last year.

Anyways, when I turn on the multimeter the milliamp reading shows a few mA even when I'm not touching anything. It usually settles down to 0 mA after about 10 seconds though.

Is this normal?

Also, when I'm checking capacitance it always shows an nF value and never gets to 0 nF.

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  • \$\begingroup\$ What does the device data sheet / user manual tell you? \$\endgroup\$ – Andy aka Dec 13 '16 at 14:01
  • \$\begingroup\$ Sounds perfectly normal to me. Near zero the inaccuracy is always the largest as the accuracy is always specified as for example 1 % of the full range + 2 digits. You need to get an accurate current or capacitor of for example half the value of the full range and measure that to be able to say anything about the accuracy of the meter. But Fluke makes high quality meters, chances are that as long as no one messed with it it will be very accurate. Even after the calibration period has expired. \$\endgroup\$ – Bimpelrekkie Dec 13 '16 at 14:04
  • \$\begingroup\$ Side note: You should not expect zero capacitance when the probes are floating open. There is a capacitor there: the probes form the electrodes, and the air between them is the dielectric. The capacitance is very low, but not zero, and will never be zero. \$\endgroup\$ – vofa Dec 13 '16 at 15:03
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Yes it is perfectly normal. Most measuring instruments need a little warm up time. This time allows electronics component to stabilise at a certain working temperature where the calibration is made. 10 seconds warm up seems about right.

As others said, it is impossible to measure a zero capacitance as there will always be a parasitic capacitance between leads and between the pcb traces of the instrument.

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