ABSTRACT
In terms of fundamental physical constants, the coulomb is measured in units of the elementary charge
e:
(8.1b)
where the relative uncertainty in the value of the elementary charge is 0.30 ppm [1].
Charge measurement
is widely used in electronics, physics, radiology, and light and particle detection, as well as in technologies involving charged particles or droplets (as for example, toners used in copiers). Measuring charge is also the method of choice for determining the average value for small and/or noisy electric currents by utilizing time integration. The two standard classes of charge-measuring devices are the electrostatic voltmeters and the charge amplifiers.
