Impact isolation class (iic)

The methods to measure the degree of impact noise isolation provided by a floor/ceiling assembly, in laboratory conditions, are described in the ASTM E 492 or ISO 140/6 standards. For field measurements refer to ASTM E 1007 or ISO 140/7. The impacts for these measurements are produced by the ?Standard Tapping Machine?, an electrically operated mechanism consisting of five 0.5 kg hammers which fall regularly and freely onto floor surface from 40 mm height at a rate of 10 impacts/second. The sound pressure levels generated in the room directly below the floor/ceiling assembly undergoing testing are then measured, for each of the 16 third-octave-bands between 100 Hz and 3150 Hz, and they are normalized according to