All people have noise tolerance limits beyond which their hearing apparatus may deteriorate. It is therefore extremely important to check, using devices called sound level meters, that the sound level in a working environment is kept below such limits. Due to the importance of such checks, a good sound level meter must supply precise indications and take note both of constant and repetitive noises, and of sudden and occasional
noises. The reduced weight, small size and the rational layout of the controls, allow these sound level meters to be used in the most demanding conditions.