Do you need CA to measure capacitor or charge?
Charge amplifers are used in micromechanical sensors. But charge is changed there because capacitor changes. And if the speed of capacitor deviation is low, it is better to use capacitor to voltage convertors.
I need to take a measure of two variables:
AC electric field
A very low AC & DC current (which will be detected by integrating method).
My need is you know any schematic for do it and for achieve the maximal compensation of operational error, already I'm using a high presicion OpAmp (AD8625), but some advices are very grateful