1.1 This practice covers the in-situ measurement of heat flux through industrial thermal insulation using a heat flux transducer (HFT).

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

1.3 This practice estimates the thermal transport properties of thermal insulation materials in-situ in field applications under pseudo steady-state conditions. It is not intended that this practice should be used as a substitute for more precise laboratory procedures such as Test Methods C177, C335, or C518.

1.4 This practice is limited by the relatively small area that can be covered by an HFT and by the transient effects of environmental conditions.

1.5 Temperature limitations shall be as specified by the manufacturer of the HFT.

1.6 While accurate values of heat flux are highly dependent upon proper calibrations under the conditions of use, it is acceptable to use the calibrations provided by the manufacturer of the HFT for comparative work between similar materials, aging, or other conditions of use.

Note 1 - Further information may be found in the literature (1-6).

1.7 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.