Simultaneous Measurement of Liquid Level and Temperature Using Capacitive Sensor

Paper presents a technique for simultaneous measurement of liquid temperature along with level of liquid using capacitive level sensor and estimators/ soft sensors. The objective of the proposed work is to develop an estimator for measuring the liquid temperature in a process tank by analyzing the available capacitive level sensor. Input-output behavior of the capacitive level sensor is analyzed for variation in liquid level and temperature variations. A non-parametric soft sensor is designed using artificial neural network and fuzzy logic techniques are used to compute the relation between the capacitive level sensor outputs for variations in liquid temperature. The designed measurement technique is validated by performing the experiment in simulation and on practical setup. Results obtained by the technique shows successful implementation of proposed soft sensor.