The Standardization of Electrical Measuring Instruments

This paper points out the advantages, both to the maker and the customer, of national standard specifications for manufactured articles. The history of standardization in England is outlined. British specifications for electrical instruments appeared first in 1909, and in improved and enlarged form in 1919. French specifications were adopted in 1921, German in 1922. The outstanding features of the three foreign specifications are compared. The British go into much detail concerning scale construction and marking, the French concerning definitions and temperature rises. The German specifications contain very good definitions of instruments and their parts, principles, etc. They prescribe severe tests for mechanical and thermal robustness, and have an elaborate scheme of symbols to indicate the grade, operating principle, kind of current, test voltage, etc. An account is then given of the consideration which the subject of instrument standardization has received in this country. The National Meter Committees have done a related piece of work by having the Meter Code prepared and revised, and have made recommendations to the makers from time to time concerning matters of instrument standardization. The Instruments and Measurements Committee of the Institute has considered the foreign specifications, and has determined by a personal canvass that a majority of American makers are in favor of standardization. However, this canvass also showed that most of them would have felt much freer to discuss proposed standard specifications rather than the abstract question as to whether specifications should be formulated.