one kg mass refers to the total mass of irridiam plattinum rod kept in the Central beuro of weight and measurement of France at 0°celcius and
one atmospheric pressure.
One meter length refers to total length of irridiam plattinum rod kept in the Central beuro of weight and measurement of France at 0°celcius and
one atmospheric pressure.
One second time refers to total time taken by Ceassium-133 atom to complete vibratration of 91923631770 times...
.
