This project belongs to the field of metrology science and technology and was supported by the former General Administration of Quality Supervision, Inspection and Quarantine. AC resistance and time constant are listed as key measurement parameters by the International Bureau of Weights and Measures. Faced with the lack of a measurement system in this field of electromagnetic measurement and the complete dependence on imports of relevant scientific research instruments, the project team carried out research on the traceability of the values of key parameters and developed the first domestic digital AC resistance precision measurement device with independent intellectual property rights that meets IEC standards has been developed, realizing the localization of high-end AC resistance instruments and filling the domestic gap in this field. The key core technologies for building an AC resistance value traceability system have been solved, and the overall research results have reached the international advanced level. High-accuracy AC resistors are core devices in precision instrumentation, integrated chip operational amplifier circuits, etc., and play an important role in smart grid, navigation, nuclear power and other fields. Overcoming the effects of distributed capacitance, residual inductance, voltage noise, leakage current, etc. is a key technical difficulty in high-accuracy measurement of AC resistance. Traditional manual measurement devices have low accuracy and low efficiency. Aiming at the needs of industrial development, improving measurement accuracy and automation is an important challenge for precision measurement of AC resistance. At present, only national-level metrology institutes in a few developed countries such as the United Kingdom and Canada have established high-accuracy AC resistance measurement devices. The measurement uncertainty is on the order of 1E-6. my country's National Metrology Institute can only measure 1k Omega; and 10k Omega; two resistance values. Domestic provincial metrology institutions rely mostly on imported measurement equipment, with an uncertainty of only 2E-4. For a long time, high-accuracy AC resistors can only be sent to foreign countries, which has greatly affected the improvement of the core competitiveness of my country's AC measurement instruments and equipment. For the first time, the project originally proposed and implemented an automatic quasi-balanced AC resistance bridge, which automatically transfers the unbalanced difference voltage through electronic circuits, and combines the Wagner branch to eliminate the influence of leakage current. Compared with traditional bridges, the measurement efficiency has been improved by tens of times; a key core component, an electronic active inductive voltage divider, has been developed to improve the accuracy of voltage ratios; The effects of series leads, voltage noise, mutual inductance, etc. are eliminated, and synchronous digital sampling technology is applied to impedance measurement, realizing fast and high-precision automated measurement at the second level; the innovative use of capacitive loss factor to experimentally verify the resistance time constant, ensuring The device is accurate and reliable. The device independently developed by the project has an AC resistance of 1 Omega;~10k Omega; continuously measurable within range, 50Hz~Measurement uncertainty of 1.8E-6 at 1kHz~4.3E-6, Time constant measurement range (1~500)ns, measurement uncertainty up to (4~6)ns。Comparison, test and verification were carried out with similar devices from the National Institute of Metrology (NPL) of the United Kingdom and the National Institute of Metrology (NMIA) of Australia. The comparison results were excellent and the technical indicators of the device reached the international advanced level. Based on the project's innovation results and applications, he presided over the formulation of 1 national standard and published 9 papers, including 1 SCI, 7 EI, and 3 authorized invention patents. The results of the project have improved my country's AC resistance measurement capabilities by two orders of magnitude, in line with the international advanced level, and broken the situation of long-term submission to foreign countries. The national technical specification "JJF1636-2017 AC Resistance Box" that participated in the formulation has been implemented, and the developed measuring device meets the technical requirements of IEC60477 -2 international standard, and this standard has been transformed into the national standard "AC Resistors for Laboratory Use"(submitted for approval). It plays an important technical supporting role in my country's AC resistance standardization work and the construction of the national measurement traceability system. The results have been applied to the traceability of quantities in many domestic measurement institutions and are widely used in power, nuclear power, aerospace and other industries. They have provided high-quality core measurement new driving force for the localization of high-end instruments, promoted Made in China 2025rdquo;, revitalized my country's instrumentation industry.