Ampere Ampere The ampere (; symbol: A), often shortened to "amp", is the base unit of electric current in the International System of Units (SI). It is named after André-Marie Ampère (1775–1836), French mathematician and physicist, considered the father of electrodynamics. The International System of Units defines the ampere in terms of other base units by measuring the electromagnetic force between electrical conductors carrying electric current. The earlier CGS measurement system had two different definitions of current, one essentially the same as the SI's and the other using electric charge as the base unit, with the unit of charge defined by
Electrical resistivity measurement of concrete to: When the electrical resistivity of the concrete is low, the rate of corrosion increases. When the electrical resistivity is high, e.g. in case of dry and carbonatated concrete, the rate of corrosion decreases. Nondestructive testing Electrical resistivity measurement of concrete Concrete electrical resistivity can be obtained by applying a current into the concrete and measuring the response voltage. There are different methods for measuring concrete resistivity. Concrete electrical resistance can be measured by applying a current using two electrodes attached to the ends of a uniform cross-section specimen. Electrical resistivity is obtained from the equation: This method suffers from