Tag: level measurement
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20.7 Capacitive Level Measurement
Capacitive level instruments measure electrical capacitance of a conductive rod inserted vertically into a process vessel. As process level increases, capacitance increases between the rod and the vessel walls, causing the instrument to output a greater signal. The basic principle behind capacitive level instruments is the capacitance equation: Where, C = Capacitance ϵ = Permittivity of dielectric (insulating)…
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20.6 Weight-based Level Measurement
Weight-based level instruments sense process level in a vessel by directly measuring the weight of the vessel. If the vessel’s empty weight (tare weight) is known, process weight becomes a simple calculation of total weight minus tare weight. Obviously, weight-based level sensors can measure both liquid and solid materials, and they have the benefit of providing…