This test method and the apparatus described are intended primarily for sealed insulating glass units positioned horizontally. If the procedure is applied to such units in other than a horizontal position, the results may not be comparable to those obtained by this procedure.

Note 1—A similar method is Test Method E 576.

1.1 This test method describes a laboratory procedure for determining the frost point within the air space(s) of sealed insulating glass units, and establishes the criteria for determining whether that point is below or above a given or specified temperature.

1.2 This test method also describes the apparatus to be used for these determinations.

1.3 The values stated in metric (SI) units are to be regarded as the standard. The inch-pound units in parentheses are for information only.

1.4 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems 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. For specific hazard statements, see Notes 2 and X1.1.