A Comparison of Two Stationary Measurement Procedures for Truck Exterior Sound Levels

SAE RP J1096 and CSA Standard Z107.22 are compared in terms of their performance as predictors of pass-by sound levels measured in accordance with SAE RP J366b. The comparison is based on the results of tests on 60 diesel trucks covering a range of ages, sound levels and configurations. The CSA procedure is found to be at least as good a predictor of pass-by sound levels as RP J1096 and can be used on smaller and noisier sites. The results of some exploratory measurements of the effects of wind and temperature gradients on the repeatability of the two procedures are also presented and discussed.