DC millivolt millivolt level table for the accurate measurement of small signals, Used in experimental testing, production testing and maintenance of the use of. Among them, the DC millivolt table testing is often used in the experiment, the thermocouples used to measure the thermal resistance of such sensitive components of the small-signal detection.
With the industrial and technological progress, by the DC-mV single-chip control table has been broadly applied to all walks of life, and More diverse functions, the use of more convenient, reliable, and much higher accuracy, And measuring DC voltage, current and resistance. In particular, micro-computer technology with the rapid development of computer giant from the past can be reduced to measuring instruments can be placed, and as the instrument controller, memory and computing devices, and its role with intelligence. DC millivolt table is commonly used measuring instruments, the use of digital manipulation can make a more intuitive, and fast response, is an ideal measurement tool millivolt range.
This paper describes the system structure and working principle, to build a DC mV meter hardware and software system design of data acquisition and processing and display part of the process. Hardware circuit by signal amplification circuit, A / D converter, microcontroller and display components, software design is the data acquisition, processing and display programming. The entire system following the completion of the process operation, that is, the output from the signal source of the mV-level voltage signal after amplification module for A / D conversion, carried out by the single-chip data acquisition, processing, and then through a keyboard display interface chip control, translation Code to send LED display driver.
Weighing system which is described by this article is centers on singlechip AT89C52. The amount of material is sensed by weighing sensor, adjusted by signal adjusting circuit, sent to AD conversionv card, then data collection and deal with by computer. Finally the result will be display by LED with the help of keyboard display interface CMOS chip HD7279
The system software is based on developed under rapid application development environment Keil C51. Experimental results indicate that the design of this system is feasible, and the system not only has good real-time characteristic and reliability, but also has practical value and popularizing prospect.
Key word: DC mV Table; Display instruments; Single-chip data; Processing and collection
