Instruments and Systems: Monitoring, Control, and Diagnostics Annotation << Back Operative measurement of the effective values of voltage and current in industrial electrical equipment P.K. LANGE, E.E. YAROSLAVKINA, V.N. YAKIMOV, E.G. KOZHEVNIKOVA The article deals with the practical implementation of methods for the rapid measurement of the effective value of voltages and currents of powerful electrical equipment for the purpose of early detection of emergency situations. The classification of methods for determining effective values of industrial voltages and currents by their instantaneous values during one half period is considered. The errors of the considered methods are studied. A method for determining the effective value of a signal by integrating it over half its period is proposed. The errors of the proposed methods, caused by the presence of the third harmonic of the analyzed signal, are determined. The structures of the systems that implement the described methods are given. It is proposed to use the described methods if it is necessary to quickly determine the effective value of a periodic non-harmonic signal during no more than half of its period. Keywords: effective value, integrator, instantaneous value, time delay device, signal trace and hold device, industrial electrical equipment. DOI: 10.25791/pribor.05.2019.629 Contacts: E-mail: lange_distance@mail.ru Pp. 01-08.