597ec778_Weights_and_Measures_Act__Definition
[0] 4. [Basic Unit] ampere [Symbol] A [Definition] 
the unit for the measurement of electric current, being a constant current that, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section and placed one metre apart in vacuum, would produce between those conductors a force equal to 2 x 10-7newton per metre of length
Weights and Measures Act
Definition