ELECTRICAL RUNOUT USING AN EDDY-CURRENT SENSOR FOR ROUNDNESS MEASUREMENTS
General Sensor TechNote Courtesy of Professional Instruments
Electrical runout is a commonly used term in the condition monitoring industry. It refers to the apparent displacement of a rotating shaft measured with inductive (eddy current) sensors caused by variations in the material electrical and magnetic properties . Despite this unavoidable error in displacement measurement, inductive sensors remain the best choice when non-conductive contaminants such as dust, water, coolant or oil are present. In this work, actual roundness measured with a capacitance sensor and roundness plus sub-surface variation measured with an inductive sensor are compared for shafts of 6061-T6 aluminum, commercially pure Grade 2 titanium, and case hardened C1117 low carbon steel.
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