ASTM E 2907/E 2907M:2013

1.1 This practice provides guidelines for acoustic emission (AE) examinations of non-pressure, paper machine rolls. 1.2 This practice utilizes a slow rotation of the roll to produce a full load cycle where load is provided by the weight of the roll suspended from its bearings or other journal support mechanism(s). 1.3 This practice is used for detection of cracks and other discontinuities in rolls that produce frictional acoustic emission during rotation. 1.4 The AE measurements are used to detect or locate emission sources, or both. Other nondestructive test (NDT) methods must be used to evaluate the significance of AE sources. Procedures for other NDT techniques are beyond the scope of this practice. See Note 1 . Note 1 - Traditional AE examination, magnetic particle examination, shear wave ultrasonic examination and radiography are commonly used to establish the exact position and dimensions of flaws that produce AE. 1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standards. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 8 .