I have a phenomenon which creates (small) displacements of charges (that I cannot quantify for now, this is the main problem, let's say that the charge surface density will be the same as when you rub an inflated balloon against your hair), and I want to measure it. My idea is to use a small capacitor (0.1 pF) which will store the displaced charges, linked to a precise oscilloscope. I need the oscilloscope to be interfaced with my pc hence someone advised me to get one on picotech.com. I guess I most of all need a very sensitive oscillo, which will be able to measure very small voltages. And I guess I need the smallest capacitance possible because of V = q/C.
What do you think of this approach ? I'm sure there are effects that I didn't take into account (I'm a mathematician, beginner in electronics), and could someone advise me which oscilloscope I could buy, please ? My budget is up to 400 euros. Thank you !