Soil PH Online Real-time Detection System Based On Moisture And Temperature Compensation

Soil pH value is one of the important parameters of soil,which affects the growth and development of plants directly.With the rapid development of detection technology,a variety of pH detection methods have been invented.However,there are many pH detection techniques,but few of them can be used in field,It is designed that a soil pH real-time detection system in this situation.Analyzed measurement methods and principles of soil pH value,moisture and temperature,and combined with the measuring accuracy and convenience,the most suitable method is selected.According to different measurement methods,designed the corresponding detection module circuit.The electromagnetic interference among modules is eliminated by reasonable distribution circuit and time-sharing power supply.Meanwhile,a software program is compiled with hardware system to realize data acquisition,display,storage and communication.It was found that the measurement of pH sensor is greatly influenced by soil moisture and temperature,In order to reduce the influence of soil moisture and temperature in soil pH measurement,a model of moisture and temperature compensation for pH sensor is proposed.Soil pH measurement values were linearly analyzed by least square method with soil moisture and temperature.The results show that the absolute error of pH measurement caused by temperature and soil moisture is reduced more than 84.5%,and the variation range of pH measurement is not more than±0.1.Compared with ZD-18 soil acidity meter,HYSWR-12V soil moisture sensor and mercury thermometer,three determinant coefficients are all above 0.99.It proves that the performance of this system is equivalent to mature products.In order to ensure the applicability of soil pH measurement in natural environment,it is explored that threshold of soil moisture for pH sensor effectively measured,which proves that this pH sensor can be effectively used when the soil volume moisture is more 5%.Experiments show that the pH sensor can be effective measured in the range of 3.06?10.36,and the detection error is-1.53%?3.51%.It is realized that the design of a high-accuracy soil pH real-time detection system.In summary,the real-time soil pH value detection system has good performance in measuring accuracy and stability.It can simultaneously measure soil pH value,moisture and temperature,and display the results in real time.It provides a stable,reliable,fast and convenient detection instrument for field measurement.