Air, tire and road temperatures substantially affect tire/road noise emission. For measuring purposes one would like to normalize measurements to a reference temperature of (say) 20 oC. This paper describes and examines the semi-generic temperature correction procedure which is presently considered for standardization in the ISO working group ISO/TC 43/SC 1/WG 27.
Based on a lot of research and extensive data compilations, the WG now thinks that it has sufficiently consistent data for proposing corrections to noise levels from measured air temperatures to a reference air temperature of 20 oC. Much of the recent work has been conducted in the ongoing European project ROSANNE. The drafts under production distinguish between two major cases: CPX (or OBSI) measurements and SPB measurements of pavement noise properties.
The paper describes what kind of data that have been used to make the decisions, their justifications, and presents the suggested temperature coefficients for various cases (i.e. for various reference tires, pavement types and the CPX/SPB methods).