The application of soil temperature measurement by LM35 temperature sensors

Consider revising medium temperature used LM35 temperature sensor, what is an economic and feasible method. This study mainly researches the applicability of LM35 temperature sensor in soil temperature testing field. Selected the sensor, and based on the theoretical equation between the sensor output voltage and Celsius temperature; introduced correction coefficient, carried through the calibration experiment of the sensor; further more, it is applied to the potted rice´s soil temperature detection. The calibration results show that, each sensor correction coefficient is different from others, but these numerical are close to 1, the linear relationship was very significant between tested medium temperature and sensor output voltage. In the key trial period of rice potted, used LM35DZ type temperature sensor to measure the soil temperature. The analysis result show that, the changing trends are basically equal both soil temperature and air temperature, and the characteristics of soil temperatures are lag. The variance analysis shows that, the difference was not significant paper film covered and without covered on soil temperature.