1.1 This practice describes the sources of variability associated with product emission results and the methods used to reduce and quantify the reported uncertainty. It is intended to assist manufacturers, product testers, product labelers, and product purchasers who make or interpret product emissions measurement results or both. 1.2 This practice identifies the individual factors that contribute significantly to the total uncertainty of an emission rate result based on the particular test methods and procedures used to make the measurement. For the purposes of this practice, volatile organic compound (VOC) emissions from a dry material at near steady-state conditions are assumed. However, the principles may also apply to other types of sources. 1.3 This practice identifies data needed to address poorly understood factors contributing to uncertainty (for example, sample heterogeneity). 1.4 This practice is an example application of the Practice D7440. As such, this practice provides the steps of the International Organization for Standardizations (ISO) Guide to the Expression of Uncertainty in Measurement (GUM) for evaluating and estimating the uncertainty associated with product emission results. A general measurement equation for VOC emissions tests of a dry material is developed in terms of the most fundamental input quantities. In lieu of a detailed discussion of statistical theory and mathematical development, several references are provided. 1.5 Example calculations of uncertainty are provided that illustrate the application of this practice. Based on current techniques and proficiency test methods, this practice describes the level of uncertainty expected for different steps of the emissions testing process. Examples of statements of estimated uncertainty of measurements are provided for inclusion in test reports. 1.6 This practice is intended for use with ASTM and other standards for measuring emission rates of VOCs from building materials and products using small-scale chambers. While this practice describes different steps of the emissions testing process and associated uncertainties, it does not describe the determination of product emission rates. 1.7 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard. 1.8 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.
This practice will provide guidance to assess the uncertainty associated with chamber emissions measurements. Improved understanding of emission measurement uncertainty through method validation and performance checks has the potential to strengthen the usefulness of test results by allowing the comparison of measurement results, establishing traceability, improving decision-making regarding product labeling, and obtaining information to improve test methods. This practice is intended to assist building product manufacturers, product testers, product labelers, and product purchasers who make or interpret product emissions measurement results or both.
Keywordsvolatile organic compounds; emissions; chamber testing; uncertainty; indoor air quality
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
Draft Under Development