Multimeter notes: Difference between revisions
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Not a standard feature, because it needs some faster processing to do. | Not a standard feature, because it needs some faster processing to do. | ||
That said, it's useful to do at all even if the error is higher, so some off-brand multimeters do it anyway. | |||
You may also want to measure the capacitor's equivalent series resistance (ESR), | |||
because an increasing, or higher, or increasingly temperature-dependent{{verify}} | |||
ESR tends to indicate an aging capacitor. | |||
...or more practically, you often look at a table (or plot) of "this capacitance-voltagerating combination should have no more ESR than X" | |||
Most standard multimeters, even the more expensive ones, ''don't'' do this, | |||
presumably because it's a bit of a specialization | |||
and takes more time so takes away from the "multimeter gives you immediate figures" uses. | |||
There are a few methods of measuring capacitance. | |||
https://electronics.stackexchange.com/questions/441383/how-do-digital-multimeters-measure-capacitance | |||
You might already have thought of the capacitor's t=RC. | |||
This means that with a known resistance, we can charge it to the , and monitor the voltage, and fill in C=t/R | |||
You generally cannot test in-circuit (you would end up measuring the largest capacitance between the points you hold to, which you often cannot know is corect), | |||
but there are some | |||