Significance and Use 5.1 The reported values of convective heat transfer coefficients are somewhat dependent upon measurement technique and it is therefore the purpose of this guide to focus on methods to provide accurate measures of heat transfer and precise methods of reporting. The benefit of developing such a guide is to provide a well-understood basis by which heat transfer performance of fluids may be accurately compared and reported. 5.2 For comparison of heat transfer performance of heat transfer fluids, measurement methods and test apparatus should be identical, but in reality heat transfer rigs show differences from rig to rig. Therefore, methods discussed in the guide are generally restricted to the use of heated tubes that have wall temperatures higher than the bulk fluid temperature and with turbulent flow conditions. 5.3 Similar test methods are found in the technical literature, however it is generally left to the user to report results in a format of their choosing and therefore direct comparisons of results can be challenging.Scope 1.1 This guide covers general information, without specific limits, for selecting methods for evaluating the heating and cooling performance of liquids used to transfer heat where forced convection is the primary mode for heat transfer. Further, methods of comparison are presented to effectively and easily distinguish performance characteristics of the heat transfer fluids. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 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. 1.4 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.
