Principle: Readings demonstrate the productive voltage based on the average value of samples in excess of a whole variety of durations of the basic frequency  H?i ngh? l?n th? nh?t n?m 2022 c?a ??ng b? công ty TNHH MTV X? s? ki?n thi?t Kon Tum Th?ng kê t? ??ng c?p nh?t khi k?t