Measurement and Research of Greenhouse Soil Temperature Based on FBG
Studying soil temperature in agricultural greenhouses is of great significance for agricultural production.In response to the problems of low efficiency and large error in measuring soil temperature field using traditional sen-sors such as thermocouples,this paper adopts a temperature sensor based on fiber Bragg grating(FBG)to monitor soil temperature changes in agricultural greenhouses.In this method,the stainless steel tube encapsulated with FBG string is vertically buried in the soil to be measured,and the wavelength of each sensor of the FBG string is demodulated by the tunable laser method and peak seeking algorithm.An experiment was conducted to measure the multi-layer temperature field of soil in a greenhouse environment.The experimental results indicate that the temperature inside the soil varies periodically in a cosine function model.As the soil depth increases,the temperature change gradually decreases.Within a certain humidity range,the higher the soil humidity,the lower the temperature of the shallow soil.The influence of soil moisture on deep soil temperature is relatively small.Solar radiation has a significant impact on the temperature of shallow soil.
fiber Bragg grating(FBG)sensor arraytemperature field
NETL
NSTL
万方数据
维普
