Non-contact electrical machine air gap measurement tool

摘要

A measuring kit for contactless measuring of the air gap distance between a frame mounted pole and core of a rotor includes a capacitance sensor which generates a signal proportional to the measured air gap, a panel meter in communication with the capacitance sensor which interprets the signal and displays the minimum air gap distance, an A/D converter also in communication with the capacitance sensor which converts the signal to a digitized signal, and a control panel which takes the digitized signal from the A/D converter, processes the digitized signal, and then displays the minimum air gap measurement. The control panel shows a graphic of the core and its surrounding poles to track the progress of the testing, and when the testing between the core and one of the surrounding poles is complete, the graphic of the pole tested visually darkens to indicate that portion of the test is complete.

主权项

1. A non-contact test method for measuring an air gap between a rotating surface and a stationary element, comprising:
affixing a capacitance sensor to a stationary element with a means for attaching, wherein the capacitance sensor is arranged between the rotating surface and the stationary element, wherein the rotating surface is a surface of a slip ring; verifying a system accuracy prior to capturing the air gap measurement; capturing an air gap measurement between the rotating surface and the stationary element with the capacitance sensor; increasing the air gap measurement by an amount equal to an offset, wherein the offset equals a thickness of the capacitance sensor plus a thickness of the means for attaching; correcting the increased air gap measurement with a piece wise linear created from a calibration curve; and displaying the corrected air gap measurement.