( Metre Convention ) [ 52 ] was signed by 17 states. This treaty established the following organisations to conduct international activities relating to a uniform system for measurements: [ 53 ] International Bureau of Weights and Measures (BIPM), [ Note 1 ] a permanent laboratory and world centre of scientific metrology, the activities of which include the establishment of the basic standards and scales of the principal physical quantities and maintenance of the international prototype standards. In 1881 first International Electrical Congress adopted the BAAS recommendations on electrical units, followed by a series of congresses in which further units of measure were defined and the International Electrotechnical Commission (IEC) was set up with the specific task of overseeing electrical units of measure. [ 54 ] This was followed by the International Congress of Radiology (ISR) who, at their inaugural meeting in 1926, initiated the definition of radiological-related units of measure. [ 55 ] In 1921 the Metre Convention was extended to cover all units of measure, not just length and mass and in 1933 the 8th CGPM resolved to work with other international bodies to agree standards for electrical units that could be related back to the international prototypes. [ 56 ] Since 1954 the CIPM committee that oversees the definition of units of measurement, the Consultative Committee for Units , [ Note 5 ] has representatives from many international organisations including the ISR, IEC and ISO under the chairmanship of the CIPM. [ 57 ] A number of