simple capacitor test circuit

I think it's one of those fringey free-energy hydrogen generators.

He's all wet. ;-)

-- Politicians should only get paid if the budget is balanced, and there is enough left over to pay them.

My mistake. Thanks Jeroen. And, I believe you are correct that it will still not be easy to measure (if at all).

G > What made you choose water?

MAT > He's all wet. ;-)

Even if it had mineral oil dialectric it's not much plate area.

John Larkin > I think it's one of those fringey free-energy hydrogen generators.

I don't think stainless fits that idea. And they usually get both hydrogen and oxygen though they could intend to throw away (vent) the oxygen.

I always thought it was neat how you can take water and break it into hydrogen and oxygen but then if you combine those two gases and ignite they can be quite energetic.

Is the energy from that process worth the cost of the electricity used to break up the hydrogen and the oxygen?

I took it for granted that it was a lossy energy conversion.

When they reconsidered this stuff for automobile use, what exactly killed that idea off?

The explosive hazard? Conversion costs? What else?

Of course not. You can't win. You can't break even. I'm surprised by the very question. What are you?

Nothing beats the convenience of a tank full of liquid fuel.

Jeroen Belleman

That's the most accurate way; known C and unknown form half the bridge, and two resistors (really, a potentiometer ) form the other half. The capacitor ratio sets the voltage division on the capacitance half, and resistor ratio sets it on the resistor half. An AC source drives both (I'd use a wall-tumor transformer to start with), and an AC meter determines a null if they're balanced. Adjust the potentiometer for best null. C1/C2 = R1/R2 when the output is minimum.

The AC meter is unnecessary, really; a speaker would do (you just listen to the signal).

Less accurate, but also effective, you could oscillate with a known resistor, in a NE555 (or otheer '555) astable circuit, and use charge-pump circuitry (two diodes and a capacitor or two) into the milliamp inputs on your multimeter. If the frequency is low enough, replace the charge pump with a flashing light or ticking speaker and use a stopwatch.