ASTM A773/A773M-01

Hysteresigraph testing permits more rapid and efficient collection of dc hysteresis (B-H loop) data as compared to the point by point ballistic Test Methods A 341/A 341M and A 596/A 596M. The accuracy and precision of testing is comparable to the ballistic methods. Hysteresigraphs are particularly desirable for testing of semihard and hard magnetic materials where either the entire second quadrant (demagnetization curve) or entire hysteresis loop is of primary concern.

Provided the test specimen is representative of the bulk sample or lot, this test method is well suited for design, specification acceptance, service evaluation and research and development.

1.1 This test method provides dc hysteresigraph procedures ( B-H loop methods) for the determination of basic magnetic properties of materials in the form of ring, toroidal, link, double-lapped Epstein cores, or other standard shapes that may be cut, stamped, machined, or ground from cast, compacted, sintered, forged, or rolled materials. It includes tests for normal induction and hysteresis taken under conditions of continuous sweep magnetization. Rate of sweep may be varied, either manually or automatically at different portions of the curves during tracing. Total elapsed time for tracing a hysteresis loop is commonly 10 to 120 s per loop.

1.2 The values stated in either customary (cgs-emu and inch-pound) units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other. Combining values from the systems may result in nonconformance with this test method.

1.3 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.