The Design Of High Precision AC/DC Multifunctional Standard Resource And Research

High precision standard source for calibration could guarantee the accuracy of the measuring instrument in the field of measurement. So the precision of standard source directly affects the measurement results. At the same time, multiple physical quantities in the process of calibration should be calibrated. Considering the high expensive and from abroad of the high precision standard source, this paper designed a high precision AC/DC multifunctional standard resource to meet the demand of the scientific research.Based on the actual measurement, this paper studied the current development situation of the standard source at home and abroad, put forward the design requirements and the design of the indexes and made the overall scheme of the high precision AC/DC multi-function standard source combining with the national conditions and reality. Then the core circuit of hardware and software such as DC voltage, the current source, voltage amplifier, feedback system, resistance simulation and control system was respectively designed in detail. And its various parts of parameters such as stability, error analysis was analyzed to ensure them reached the design of the indexes.The application of STM32F205RET6 as the control core of the whole system improved the operation speed and precision of the system. At the same time, the high precision analog-to-digital converters AD5791 that producted by Amercan ADI company as the core of the digital to analog conversion didn’t only control the output of the DC reference but also regulated the amplitude of the signal source output. The synthetic low frequency signal source with the principle of phase-locked loop reduced the noise and error, and the power was amplified to the required range through the corresponding amplifier, the feedback system controlled its accuracy to make sure the stability of system. In addition, this paper utilized a calibration technique based on the least square method to eliminate the system error for the measured data and improve the precision of standard source. Finally, the accuracy and stability of each parameter has been tested in detail, the test results meet the design requirements.The designed high precision AC/DC multifunctional standard resource with good output stability and high accuracy greatly improves the measurement accuracy of domestic test in the field of measuring and testing, it could widely been used in high resolution instrument calibration and lays the foundation of the research for higher accuracy of detection standard source in future. The research improves the ability of national independent innovation, reduces the foreign market monopoly on high precision instruments and has made an important .contribution on scientific research level and the economic development of our country.