# Electrostatics, measurement of charge

How did physicists come up with a standard for measuring charge? How an electrical measurement of charge was made?

You can of course find this on wiki...or many other places.

Today, charge is related to the elementary charge e

The SI unit of charge, the coulomb, "is the quantity of electricity carried in 1 second by a current of 1 ampere A". Conversely, a current of one ampere is one coulomb C of charge going past a given point per second:

$$1 A = 1 \frac{C}{s}$$

The Ampere is defined by the elementary charge, see e.g. wiki for more detail than you probably want.

Practical measurement - if you have a capacitor of known strength, you can measure the charge on it with a voltmeter.

Hope that helps.