Comparative Testing 2014–2018 of Thermal Conductivity for Thermal Insulation Products—The European Keymark Experience for More than 45 Equipment at 21 Test Institutes

Abstract

This paper describes the comparative testing of thermal conductivity on a range of thermal insulation products used in the construction of buildings performed during 2014-2018. Further this paper describes the procedure on how to establish and include new expert apparatus in the scheme, when older apparatuses are outdated and scrapped. Comparative testing within the Keymark scheme has been performed since 2001, results have been presented at ITCC 27 and ITCC 32 (Rasmussen, ITCC27, 2003 and Rasmussen, ITCC32, 2014); this paper concludes the latest comparative testing. The comparative testing is arranged by the CEN Keymark scheme for voluntary certification of insulation within Europe, and measurements have been performed using 52 instruments at twenty-one registered laboratories. Comparative testing is performed using sets of test specimens with a unique thermal conductivity value established according to the Keymark scheme rules, developed by experts from the most respected European laboratories. These experts include most of the laboratories responsible for characterizing the European certified reference material (IRMM 440) for thermal conductivity measurements on thermal insulation products (Quin, Venuti, De Ponte and Lamberty, 2000). Expert apparatuses is defined to be Guarded Hot Plate apparatus (GHP). Establishment of new expert apparatuses is following the procedure for the first comparative testing carried out between the original eight Expert Group Laboratories within the Keymark scheme, thereby verifying and confirming the new expert apparatus to be within the original standard variation obtained by the original expert laboratories.

The voluntary Keymark scheme works alongside the mandatory CE conformity mark used within the European Union and includes rigorous auditing and assessment of measurement capability, which provides a high level of confidence in measured thermal conductivity values produced by registered laboratories. Information on the Keymark scheme can be found on the web-site: www.insulationkeymark. org.