Technikatörténeti szemle 10. (1978)

A MÉRÉS ÉS A MÉRTÉKEK AZ EMBER MŰVELŐDÉSÉBEN című konferencián Budapesten, 1976. április 27–30-án elhangzott előadások II. - Kind, D.: Az elektromos mértékegységek fejlődése a SI rendszerben

among them again eminent scientists of that time. At this Conference, like 1881 in Paris and 1893 in Chicago, the delegates adopted a set of base electrical units as decimal multiples or sub-multiples of the corresponding electromagnetic CGS units. Further a system of international electrical units was adopted representing the base units with sufficient accuracy for purpose of measurements: the international ohm the international ampere the international volt the international watt. With the resolutions on these units the delegates of the London Conference followed the recommendations of the preliminary Conference in Berlin. Furtheron, the delegates recommended the foundation of an ,,International Electrical Laboratory" as already suggested and discussed at the preliminary Conference in Berlin. This Laboratory should preserve and maintain the international electrical standards; it should, however, be independent of the existing national standardizing laboratoires (12). The inclusion of the electrical units into the International System of Units 1960 The international cooperation was interrupted also in the field of metrology by the First World War. However, already in 1921 an important step was done with the revision of the Metre Convention by extending the field of responsibility of the International Committee on Weights and Measures to electrical and photometric units. Thus the task discussed in 1905 in Berlin was assigned to the BIPM at Sevres. In 1948, after the work had again been interrupted for a longer time by a war, it was decided to reintroduce ,,absolute" electrical units, this time, however, not on the base of the old CGS system but on the base of the from Giorgi originating MKSA system with the base units metre ...... kilogram second ampere. 'I These four base units are part of the International System of Units (SI), adopted by the 11th General Conference of Weights and Measures in 1960, which, in spite of certain transition difficulties, has been introduced world wide, due to its generally known advantages. Today, more than 40 countries are adhering to the Metre Convention, whose organs took over the responsibility to ensure the propagation of the SI. Except for the kilogram, which still is represented by a material standard (the international prototyp of the kilogram), the determination of the base units is related to fundamental physical constants: