ASTM C1058/C1058M-10(2023)

4.1?The various methods for measuring and calculating thermal properties provide data and information for manufacturer's published information, for comparison of related products, and for designers and users to evaluate insulation products for particular applications. For these purposes it is advisable to provide basic data and information produced under standard temperature conditions.

4.2?It is possible that thermal properties of a specimen will change with mean temperature, with temperature difference across the specimens, and with high temperature exposure. Data and information at standard temperatures are necessary for valid comparison of thermal properties.

4.3?The mean test temperatures to measure thermal properties shall be selected from those listed in Table 1. It is recommended that thermal properties of insulation materials be evaluated over a mean temperature range that represents the intended end use. For this situation, the lowest and greatest mean temperatures need to be within 10?C of the maximum and minimum mean temperature of interest. The temperature differences for any chosen mean temperature will depend upon both the thermal insulation application (see appropriate materials specification), the method of evaluation, and the limitations of the apparatus. Temperature differences or relevant temperature conditions required by ASTM material specifications shall take precedence over those recommended in this practice.

1.1?This practice covers standard mean temperatures for reporting thermal properties of thermal insulations, products, and materials, and of related systems and components, both insulated and uninsulated.

1.2?Thermal properties shall be determined as a function of temperature by standard test methods. (Test Methods C177, C201, C335/C335M, C518, C745, C1114, C1363, Guide C653, and Practice C687, all in combination with Practice C1045.)

1.3?This practice recommends standard conditions for use in testing and evaluating thermal properties as a function of temperature by standard test methods.

1.4?General applications of thermal insulations include:

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 standard.

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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.