Nicichon FG fine gold

Hi my friends

Today come to my brand Nichichon FG 470uf 63V capacitors.

I measured everything and saw the max. 442.5uf.

This is normal?

The rest of the other capacitors are fine
 

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Electrolytic capacitors measure closer to nominal with 100Hz or 120Hz sinewave test frequency. Maybe this tester uses 1kHz to can also accommodate film and ceramic types but to still report somewhere near real for all. The higher the test frequency, electrolytics tend to be reported smaller. Fully fledged LCR meters allow you choose 100-120-1000-10000-100000Hz.
A typical DMM usually shows electrolytics closer to nominal. Mostly adopting a different test signal, looks like timing a ramp up repetitive charge. Good for estimating uF only. Especially Nichicon audio series caps tend to measure very close to nominal on a DMM.
 
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I have an impedance bridge that measures capacitors very accurately at 1kHz. It's been professionally calibrated. I also have a Fluke DMM with a capacitance-check feature. Electrolytic capacitors always tend to measure lower on my bridge than on the Fluke. I've never been able to find out what test the Fluke uses. When I put a frequency counter on the Fluke on capacitance check, I couldn't get a reading, and I can't find a description of the test in the meter manual.

And Nichicons, in particular, often seem to measure low. When you think about it, more foil area = more capacitance, so the manufacturers probably save money on making them lower than nominal value. Over hundreds of thousands of capacitors, I guess it adds up.
 
I have an impedance bridge that measures capacitors very accurately at 1kHz. It's been professionally calibrated. I also have a Fluke DMM with a capacitance-check feature. Electrolytic capacitors always tend to measure lower on my bridge than on the Fluke. I've never been able to find out what test the Fluke uses. When I put a frequency counter on the Fluke on capacitance check, I couldn't get a reading, and I can't find a description of the test in the meter manual.
Here are oscilloscope captures of four DMM models capacitance mode output signals I took. Connected at their test leads with a coax that has crock ends and a male BNC on its other end. They send out a similar sawtooth style periodic signal of very different frequency each. The Fluke 87V differs by sending mainly negative going very short lasting pulses.
 

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  • ANENG AN8008 cap test.png
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  • UNI-T UT139C cap test.png
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  • FLUKE 87V cap test.png
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  • FLUKE 87V positive peaks detail.png
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