AC-frequency parameters of the development of digital multimeter Abstract Multimeter use of single-chip control, computing functions, according to the formula of discrete points and discrete Fourier transform, the power system parameters based on a sampling of ideas to exchange, at the same time all the way to achieve the frequency of the alternating current frequency, voltage rms, current RMS measurements. Calculation and analysis software of active power, reactive power, power factor, fundamental RMS voltage, RMS voltage total harmonic parameters such as the use of digital potentiometers, the system self-calibration, automatic conversion range. System to fully exploit the computing power of single-chip software instead of hardware circuits, so that greatly simplify the hardware circuit. Digital Multimeter-frequency alternating current parameters can be achieved along the way at the same time-frequency alternating current value of the various power, voltage rms, current rms measurement parameters. It uses single-chip control, computing features to the software instead of hardware circuit design, the use of alternating current sampling methods, using a variety of calculation and analysis software, RMS, active power, reactive power, power factor and other parameters, so that greatly simplify the hardware circuit . The system uses a digital potentiometer to facilitate accurate adjustment, long service life, the impact of the external environment by a small, stable performance characteristics of the circuit design with self-calibration, range can be automatically converted, high measurement accuracy, stable performance and so on. Keywords: e-commerce online store dynamic pages JSP Access