From the large number of criteria that take into account the physical and technical nature of analog electrical measuring instruments, three have been singled out in the proposed classification which define the purpose, the metrological features (method of realizing the measuring process), and the technological features (nature of the major subassemblies). All analog instruments can be classified in accord with these criteria regardless of their structure, complexity of the equipment, and operating principles of the measuring transducer.
Translated from Izmeritel'naya Tekhnika, No. 11, pp. 53–54, November, 1971.