The base unit of electric current in the International System of Units that is equal to a constant current which when maintained in two straight parallel conductors of infinite length and negligible circular sections one meter apart in a vacuum produces between the conductors a force equal to 2 x 10-7 newton per meter of length.

【电】安培(电流单位；符号: A )。一安培等于二条截面为圆形无限长且极细之导线，相距一公尺平行放置于真空中，通以同值恒定电流时，使每公尺长之导线间产生千万分之二牛顿作用力之电流。