ASTM C1130-24 PDF

SIGNIFICANCE AND USE 5.1 The application of HFTs and temperature sensors to building envelopes provide in-situ data for evaluating the thermal performance of an opaque building envelope component under actual environmental conditions, as described in Practices C1046 and C1155. These applications require calibration of the HFTs at levels of heat flux and temperature consistent with end-use conditions. 5.2 This practice provides calibration procedures for the determination of the heat flux transducer sensitivity, S, that relates the HFT voltage output, E, to a known input value of heat flux, q. 5.2.1 The applied heat flux, q, shall be obtained from steady-state tests conducted in accordance with either Test Method C177, C518, C1114, C1363, or, for cryogenic applications, Guide C1774. 5.2.2 The resulting voltage output, E, of the heat flux transducer is measured directly using (auxiliary) readout instrumentation connected to the electrical output leads of the sensor. Note 1: A heat flux transducer (see also Terminology C168) is a thin stable substrate having a low mass in which a temperature difference across the thickness of the device is measured with thermocouples connected electrically in series (that is, a thermopile). Commercial HFTs typically have a central sensing region, a surrounding guard, and an integral temperature sensor that are contained in a thin durable enclosure. Practice C1046, Appendix X2 includes detailed descriptions of the internal constructions of two types of HFTs. 5.3 The HFT sensitivity depends on several factors including, but not limited to, size, thickness, construction, temperature, applied heat flux, and application conditions including adjacent material characteristics and environmental effects. 5.4 The subsequent conversion of the HFT voltage output to heat flux under application conditions requires (1) a standardized technique for determining the HFT sensitivity for the application of interest; and, (2) a comprehensive understanding of t... SCOPE 1.1 This practice, in conjunction with either Test Method C177, C518, C1114, or C1363, establishes procedures for the calibration of heat flux transducers that are dimensionally thin in comparison to their planar dimensions. 1.1.1 The thickness of the heat flux transducer shall be less than 30 % of the narrowest planar dimension of the heat flux transducer. 1.2 This practice describes techniques for determining the sensitivity, S, of a heat flux transducer when subjected to one dimensional heat flow normal to the planar surface or when installed in a building application. 1.3 This practice shall be used in conjunction with Practice C1046 and Practice C1155 when performing in-situ measurements of heat flux on opaque building envelope components. This practice is comparable, but not identical, to the calibration techniques described in ISO 9869-1. 1.4 This practice is not intended to determine the sensitivity of heat flux transducers used as components of heat flow meter apparatus, as in Test Method C518, or used for in-situ industrial applications, as covered in Practice C1041. 1.5 This practice does not preclude the laboratory calibration of heat flux transducers for large-scale insulation systems operated at temperatures lower or higher than that for building envelope components. For these applications, the heat flux transducers shall be calibrated at the temperatures that the transducer will be used. 1.5.1 For cryogenic applications, the test apparatuses described in Guide C1774 are acceptable methods for calibration. 1.6 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard. 1.7 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information only and are not considered sta...