电性能核查校准对FDR自动土壤水分观测仪观测结果的影响研究

Study on the Electrical Performance Verification Calibration Effect on FDR Automatic Observation Instrument for Soil Moisture Observations

FDR( Frequency Domain Reflection)自动土壤水分观测仪是基于土壤中水分变化时介电常数随之改变的特性,通过LC 振荡电路频率响应变化,利用土壤水分频率关系模型计算输出土壤体积含水量。随着观测仪使用时间的增长,传感器的电气性能会发生变化。因此,要保证传感器测量的准确度,使用一段时间后就要对传感器进行核查校准,将不合格的传感器进行更换。本文研究分析了以两年为周期FDR自动土壤水分观测仪电性能核查校准前后观测数据。通过分析结果得出:核查校准后观测数据准确性提高了0. 05%,因此,对自动土壤观测仪进行电性能核查是必要的。

FDR ( Frequency Domain Reflection) automatic soil moisture observation instrument is based on the change of the dielectric constant when the soil moisture changes. The frequency response of the LC oscillation circuit is used to calculate the volumetric water content of the output soil by using the soil water frequency relationship model. As the life of the scope increases,the electrical performance of the sensor changes. Therefore,to ensure the accuracy of the sensor measurement,the sensor should be checked and calibrated after a period of use,and the unqualified sensor should be replaced. This paper analyzes the observation data of the FDR automatic soil moisture observation instrument before and after calibration in two - year cycle. According to the analysis results,the accuracy of the observation data after verification and calibration is improved by 0. 05%. Therefore,it is necessary to check the electrical performance of the automatic soil observer.