Part I Units and Standards of Measurement
2 United Kingdom primary standards and authorised copies of the primary standards.
1
The Secretary of State shall cause to be maintained standards of the yard, pound, metre and kilogram which shall be the standards (in this Act referred to as “United Kingdom primary standards”) by reference to which, in the United Kingdom, all other standards of those units and of any other unit of measurement derived wholly or partly from any of those units shall be maintained.
2
The Secretary of State shall from time to time as may appear to him expedient cause—
a
the value of each of the United Kingdom primary standards to be determined or redetermined, and
b
any authorised copy of any of those standards to be compared with, and its value determined or redetermined by reference to, that standard,
in such manner as he may direct.
3
The United Kingdom primary standards shall be—
a
in the case of the yard, the bar described in Part I of Schedule 2 to this Act;
b
in the case of the pound, the cylinder described in Part II of that Schedule;
c
in the case of the metre, the bar described in Part III of that Schedule;
d
in the case of the kilogram, the cylinder described in Part IV of that Schedule.
4
The copies of the United Kingdom primary standards of the yard and pound which are described in Part V of Schedule 2 to this Act and deposited as mentioned in that Part shall for the purposes of this Act be authorised copies of those standards.