With the continuous development of modern technology, the function of intelligent digital form is growing, the scope of its use will be more extensive. Intelligent use of digital equipment will not only improve the measurement accuracy, but also improve the electrical measuring the degree of automation technology ,and to improve verification efficiency of the workers.
selected frequency level meter is high sensitivity, high level of precision measurement instruments, with the support of level oscillator constitute a complete transmission test equipment, in the power system for testing electricity power line carrier and the level of protective equipment, gain, Attenuation, and the measurement of debugging of the protection of high-frequency transceiver.
with the development of microelectronics technology Selected frequency level meter and the level oscillator continuously upgrade, and using international advanced digital direct synthesis (DDS) to achieve a frequency stability of the crystal and the level of technical performance significantly improved, and the Equipment will to the increasingly integrated, smaller and universal.
In this paper, contains Simple Comprehensive Test Instrument(Selected frequency level meter and the level oscillator) and its specific design, Selected frequency level meter used AC/DC converter chip AD637 measured the exchange of signals with the RMS voltage converter for the same DC voltage, then after A / D converter sample be tested ,to get the voltage signal RMS . Level oscillator using Direct Digital Synthesis chip AD9851 for Synthesis, output frequency, gain control of the sine wave and a frequency of testing and increase the frequency of data storage playback.
Keywords: Selected frequency level meter level oscillator DDS Direct Digital Synthesis
