PC-Based Instrumentation System for the Detection of Moisture Content of Tea Leaves at Its Final Stage

This paper describes a PC-based instrumentation system designed for online monitoring of the moisture content (MC) of tea leaves at its final stage. A fringe-field capacitive probe is used as a sensor to detect the MC of a tea leaf sample. The probe is mounted on the shaft of a stepper motor. The stepper motor is used to shake the tea leaf samples to obtain similar compactness for all tea leaf samples whose MCs are to be monitored. The introduction of shaking facility in the measurement procedure ensures consistency of measurement. The three-dimensional finite element method is used for the determination of field distribution around the surface of the sensor and the capacitance of the sensor

[1]  Design and analysis of electro optic sensor by finite element method , 2000, Proceedings of IEEE International Conference on Industrial Technology 2000 (IEEE Cat. No.00TH8482).

[2]  Ge Courville,et al.  Electric Field Probes for Quantitative Moisture Measurements in Building Materials , 1989 .

[3]  Suresh C. Saxena,et al.  Capacitive Moisture Meter , 1981, IEEE Transactions on Industrial Electronics and Control Instrumentation.

[4]  L. Byrd,et al.  Moisture content estimation in paper pulp using fringing field impedance spectroscopy , 2004, IEEE Sensors Journal.

[5]  R. N. Karekar,et al.  Miniaturized nondestructive microwave sensor for chickpea moisture measurement , 1999 .

[6]  T. Lasri,et al.  Microwave sensor for moisture measurements in solid materials , 1991 .

[7]  Peter P. Silvester,et al.  Finite elements for electrical engineers: Finite Elements for Electrical Engineers , 1996 .

[8]  Anton TenWolde,et al.  Accuracy of Wood Resistance Sensors for Measurement of Humidity , 1996 .

[9]  J. Boaventura Cunha,et al.  Soil moisture sensor with built-in fault-detection capabilities , 1998, IECON '98. Proceedings of the 24th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.98CH36200).