Abstract :
Summary form only given. Constructed with simple circuits and readily available IC elements, the meter provides high linearity and long-term stability. It can be used to measure electric power on single phase, three phase with three lines, and three phase with four lines. In the calibration of two experimental models with the meter, for measuring voltage ranging from 100/ square root 3-350 V, a current range of 0.1-30 A, a power factor cos phi =1, 0.5L and 0.866C, the accuracy was found to be better than 1.5*10/sup -4/. Because of the intelligent compensation by the microcomputer, only a single-chip IC multiplier is used as the basic element of the measuring circuit. Hence, the circuits can be made simple, compact, stable, and reliable. The instrument can be time controlled. The errors are automatically corrected by the microcomputer.<>
Keywords :
computerised instrumentation; digital instrumentation; error compensation; measurement errors; microcomputer applications; power measurement; 0.1 to 30 A; calibration; error correction; four lines; intelligent compensation; linearity; microcomputer-compensated digital power meter; single phase; single-chip IC multiplier; stability; three lines; three phase; Calibration; Circuit stability; Current measurement; Electric variables measurement; Linearity; Microcomputers; Phase measurement; Power measurement; Reactive power; Voltage measurement;