The moisture content of most core materials is related to such properties as electrical properties (such as dielectric constant, loss tangent, and electrical resistance) and mechanical properties (such as strength and modulus). The amount of weight the structure may gain by the core absorbing water is also important. It should be noted that in a sandwich panel there are facings bonded on two sides of the core that affect the amount of water absorbed by the core.

1.1 This test method covers the determination of the relative amount of water absorption by various types of structural core materials when immersed or in a high relative humidity environment. This test method is intended to apply to only structural core materials; honeycomb, foam, and balsa wood.

1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given may be approximate.

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.