national measurement act 1960
determination by the national standards commission
Recognized-Value Standard of Measurement of Density
Standard Mean Ocean Water
In pursuance of paragraph 8A(1)(a) of the National Measurement Act 1960, the National Standards Commission hereby determines that the magnitude of the density of standard mean ocean water at a temperature of 3.99°C and at a mean pressure of 101 325 Pa shall be a recognised-value standard of measurement having the exact value 999.975 kg.m-3.
For the purposes of this Determination standard mean ocean water is pure water, free of dissolved gas, in which the ratio of the number of oxygen atoms of mass number 18 to the number of oxygen atoms of mass number 16 is 0.002 005 and the ratio of the number of deuterium atoms to the number of hydrogen atoms is 0.000 155 76.
Dated this 21st day of March 1985
The common seal of the national T.J. PETRY
standards commission was hereto
affixed by authority of the Commission
in the presence of