Insulation board or thermal conductivity measurement reference plate

摘要

A device comprising at least one base plate and at least one cover plate held in a frame with the void regions containing a microcellular filler uses carbon black to colour the filler. Also claimed is preparation of the device by gluing or welding the plates and frame together. Preferably long term thermal conductivity is less than 30 mW/m.K and long term thermal conductivity stability is more than 1a (1 year). The plates and frame comprise thermoplastic or foamed plastic, preferably hard polyurethane foam with an open cell structure. Metal oxide or (preferably) silica aerogel particles with an average size of 0.001-5 mm is used as the filler.