Accuracy in the measurement of sound levels in situ with sound level meters

Differences among readings on different sound level meters when measuring the same signal have been studied with the object of specifying the measuring accuracy in in situ measurements. Three sound level meters of different origins have been used, and five kinds of noises have been measured in five places of different acoustical characteristics. The measurements were performed by three experienced operators. Results of the standard deviation of the measurements made by different operators using different SLM are supplied.