Multifunctional Admittance-Type Sensor and Its Instrumentation for Simultaneous Measurement of Liquid Level and Temperature

The admittance-type-level sensor is used for continuous level measurement in both metallic and nonmetallic tanks. However, the use of this sensor is limited because of the significant nonlinearity and cross-sensitivity. In this work, the authors have proposed the concept of a double-electrode admittance-type-level sensor. The said level sensor measures the level and the temperature of a conductive liquid. The multifunctional measurement is possible by the detection of the extent of cross-sensitivity using fuzzy logic and decomposition of the measurement variables. The experimental prototype of the sensor and associated instrumentation have been developed, and from the experimental results, it is found that the error in the measurement is consistently distributed and within the range of 1.86% for the level and 2.73% for temperature, which demonstrates the appropriateness of the design. This measurement system and sensor design can be implemented in the boiler-drum-level measurement for better drum-level control.