Sound level

Sound Level

Physical dimension for measuring sound, expressed in decibel. Decibel is defined as the logarithmic ratio of a measured sound pressure and the reference sound pressure of the human threshold of audibility for the 1,000 Hz sound. By means of incorporated filters the sound pressure receivers used for measuring also allow the consideration of the volume on expressed in phons. The measurement is taken at a distance of one meter to the sound source. For industrial trucks the maximum permissible sound level is 90 dB.