Air Pipe Head,Jis Air Pipe Head,Marine Air Vent Head,Marine Air Pipe Head Jiangsu Hida Marine Valve Co., Ltd , https://www.haidavalve.com Roundness detection can basically be summarized as two basic types of fixed axis measurement and indeterminate axis measurement. The method of roundness detection with a fixed axis rotation is represented by a roundness meter. Whether it is the rotation of the probe or the object to be tested, there must be a reliable rotating shaft system with certain accuracy requirements to maintain a stable axis of rotation. . Two-point method, three-point method and other roundness detection methods are measurement methods of indeterminate axes, especially the three-point method.