Tyz-3 Intelligent Integrated Soil Nutrient Tester, Research And Development,

With the rapid development of the microelectronics and computer technology, especially the development of the SCM (Single Chip Microcomputer), the great changes have taken place in the area of instrumentation, and a new generation of instruments--intelligent instruments are becoming known. In order to meet the requirement of the modem agriculture, a new-style intelligent soil nutrition gauge was designed and manufactured in the period of time from June 1999 to October 2000. This paper briefly summarized the development of the soil nutrition gauge inside and outside country and discussed the measuring principle and the designing of the software and hardware of the gauge. The several key points in the research were highlighted in this paper: 1 By studying the micro adjusting system of the digital potentiometer, the starting point from which the output voltage was monotonously increasing was found. 2.. By simulating and mathematically analyzing the circuit of the conductivity part of the gauge, we got the gauge's shortest echo constant and the mathematical model of the electric conductance. 3.. By studying the mathematical model of the voltage dividing resistor, we got the optimal value of the resistor. 4.. By studying the makeup of the expert system ,we found an effective way to setup the expert consultation system on the SCM system. The conclusions above had been used to optimizing the designing of the gauge's software and hardware and greatly improved the measuring accuracy and working efficiency. The more important was that they provided the theoretical basis and powerful tools for the future development of the instrument.