The standard unit of electric current, the ampere, is one of the seven base units in the International System of Units. But measuring a current exactly in amperes is not an easy task. In fact, in 1990 ...

A nanoampere (nA) is a unit of electric current in the International System of Units (SI), defined as one billionth of an ampere (A), or 1 / 1,000,000,000 A. This small scale of measurement is ...