Study On Design Of Instrument For Soil Humidity Measurement Based On Dual-Spectrums

It is key technology to measure and control soil humidity when actualizing precision agriculture. It is helpful for crop growth, improving fertilizer's using ratio and avoiding polluting groundwater to inspect soil moisture at real time. The traditional methods exist some disadvantages, for example, long measuring period, cockamamie working and high measuring cost. Therefore, it is urgent affairs to develop a measuring instrument about soil moisture which have high precision, fine reliability and good real time.According to practical demand about agriculture production and actualizing precision agriculture inland, this paper researched and designed a measuring meat about soil humidity based on two spectral bands and having real time, non-contacting and celerity and applied near infrared spectrum analysis technology. The research is based on theoretical study about measuring soil percentage of moisture using near infrared spectrum. Main work as follows:1. Carrying out measuring experiment about soil humidity using spectrum actinograph which has advantages of high precision and hand-portable. Analyze the relationship between soil humidity and soil spectrum reflectivity to provide theoretical gist for near infrared spectrum to measure soil humidity.2. Researching the principle and production about measuring moisture by near infrared spectrum, comparing measuring other matter's moisture by near infrared spectrum and then founding the model of soil moisture measuring based on two spectral bands.3. Considering the request of low power consumption and reliability about the system, founding the system's hardware flat roof adopting advanced and integrated CMOS chip and spectrum testing technology.4. Applying some measures to improve the whole system's function efficiency and measuring precision, for example, modularizing design idea, one another nesting between C language and assembly language and average smoothing mean which can avoid pulse disturbing and so on.5. Regressively analyzing the datum by applying least square so as to complete demarcating the system. The results indicated that the system has better recurrence and can realize real-timely measuring soil humidity by testing repeatability.6. This testing system can not only be applied for measuring soil humidity, but also provide a method and platform for exploiting other intellectualized instruments by near infrared spectrum technology.