A new method measuring electrical conductivity of nutrient solutions on-line

For the problem of measuring the electrical conductivity of nutrient solutions in a closed soilless growing system in greenhouse agriculture, a method fitting the model of an electrical conductivity sensor step by step is put forward. The method of sensor calibration and nutrition solution measurement on-line is constructed also. The process of measuring electrical conductivity is introduced in the paper. The application results demonstrate that the model constructed in the paper fits the performance well, and the new method can be widely used in engineering in a concise way.