农田土壤pH值和电导率采集仪设计与试验

Design and Experiment on the Field Information pH Value and Electrical Conductivity Acquisition Instrument

设计开发了测量pH值和电导率的农田信息采集仪。在探讨该仪器测量原理和软硬件设计的基础上,分别采用两点校正法和配比KCl溶液法对采集仪的pH值和电导率测量进行了标定试验,并在一块黄豆田间隔14 m×14 m进行土壤采样,共采土样15个,对标定方程进行了验证试验。结果表明,土壤pH值标定结果和准确值的相对误差小于1%,土壤电导率相对误差小于14%;土壤pH值标定结果和准确值线性回归模型检验显著性概率为0.047 8,决定系数为0.897 8;土壤电导率标定结果和准确值线性回归模型检验显著性概率为0.000 4,决定系数为0.971 6,所建立的pH值和电导率标定方程都是可靠的。

A field information acquisition instrument to measure the soil pH value and electrical conductivity （EC） was designed. Based on the measurement theory and the software and hardware design of the instrument, the calibration test to the acquisition instrument measuring pH value and electrical conductivity by means of two-point and the standard KCl solution was carried out. Then 15 soil samples were taken from a piece of bean field with the sampling interval of 14 m×14 m. The validation test to the calibration equation was carried out. The results showed that the relative error between the calibration result and the accurate value for soil pH value is less than 1%, and the relative error between the calibration result and the accurate value for soil EC is less than 14 %, the linear regression model significance probability of the soil pH value calibration results and exact value is 0.047 8, R2- 0.897 8, the linear regression model significance probability of the soil EC calibration results and exact value is 0.000 4, Ra= 0. 971 6, it is proved that the calibration equations of the pH value and EC are reliable.