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In scientific research, processing and manufacturing, many areas of weak signals (such as voltage, current, resistance, etc.) need to accurately measure, in which micro DC resistance measurement is a weak signal detection in the field one of the more difficult part, such as the metal contact resistance, welded metal resistivity changes, the resistance value is very small. Therefore, the micro-resistance measurement has a very important practical significance, it is necessary to test resistance at DC micro to study the issue and get relevant results.In this paper, measurement theory, hardware, software and debugging of four parts to discuss micro-precision DC Resistance Tester development and design process. First introduced the noise source, error elimination method, the circuit measurement comparison choice, selection of measurement based on current source theory, and theoretically leads to the high-precision DC Micro Tester hardware and software design of the technical route. Then in turn introduced the overall hardware design, error analysis and error over all aspects of a solution to expand sources of constant power supply design, data collection design, scale-up design, data conversion design, the main control unit design, power design, data design and communication design; and gives software solution, that is, the master program, data acquisition subroutines, algorithm for data processing, data conversion routines, display routines, and software reliability design part of the design; followed by the debug tester the results of its analysis, the tester is given the overall conclusions and outlook.
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