Standards of Weights and Measures Act : Base unit of length. Indian Bare Acts :

Standards of Weights and Measures Act,1976

Act No : 60

Section : Base unit of length.

5. Base unit of length. (1) The base unit of length shall be the metre. (2) The "metre" is the length equal to 1650 763.73 wave lengths in vacuum of the radiation corresponding to the transition between the levels 2p-10 and 5d-5 of the krypton-86 atom.