The use of a coaxial capacitor as a capacitance sensor for phase percentage determination in multiphase pipelines

Simple capacitors using multi-coaxial-cylinder configurations are designed in this work to determine both the volume and weight fractions in two-phase pipelines, Some were constructed with solid cores (two and three-coaxial-cylinder type) and the other (two-coaxial-cylinder) with hollow core; both were used as capacitance sensors. The theoretical and experimental results show that the solid core sensor exhibits a linear relationship between the measured capacitance and the volume fraction in both the static dynamic flow, while the hollow core type sensor shows a nonlinear relationship. For the latter type a linearization equation was derived. Greater sensitivity, linearity, and simplicity of construction make the suggested sensor design even more practical than the capacitance sensors adopted before.