This part 4 of this standard provides specific technical criteria for the assessment of laboratoriesto undertake steady-state heat transfer property measurements on products and components usingcalibrated or guarded hot box apparatus in accordance with EN ISO 8990:1996, including itsapplication to doors and windows in accordance with EN ISO 12567, or using a heat flow meterin a hot box apparatus in accordance with EN 1934:1998.It complements the common criteria in part 1. Guidance is given on the organization and contentsof the equipment manual, the calibration and maintenance files and the measurement proceduredocument.It provides information on mandatory equipment performance specifications and equipmentdescription. It supplements error analysis and calculations for the equipment design not suppliedin EN ISO 8990:1996, EN 1934:1998 and related standards.It provides information on experimental procedures suitable for the assessment of instrumentaccuracy.