3.1 Insulating firebrick (IFB) are classified by their bulk density and reheat change (see Classification C155). This test method defines thermal stability by measurement of IFB's reheat change following 24 h at a test temperature.

3.2 Since this test exposes the entire sample to an isothermal temperature condition, the user should be aware that most applications for IFB involve a thermal gradient which may cause the IFB's dimensions to change differentially.

1.1 This test method covers the determination of the permanent linear (and volume) change of insulating firebrick upon reheating under prescribed conditions.

1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.

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.