Spectra Tech employes sophisticated equipment and software to measure and document the “Apparent” (AIIC) or “Field” (FIIC) Impact Insulation Class values of demising interior elements of construction, including floor / ceiling assemblies. We can also provide assistance in designing solutions to increase the sound isolation provided by demising construction.

  • This is the “field” (F) version of testing normally done by product manufacturers to rate the Impact Insulation Class (IIC) performance of a product or material when tested in an ideal laboratory setting. IIC performance values are not always obtainable in the field, due to inherent deficiencies associated with field construction.

    Spectra Tech Ltd  field test procedures

  • The Field Impact Insulation Class (FIIC) Curves were developed to form a universal standard by which the noise caused by impact on surfaces (e.g., a floor / ceiling assembly) as heard on the floor below on in abutting areas could be quantified.
  • To test the transmission of impact sound through a particular construction, a reference standard “tapping machine” is employed to produce a constant force from a series of hammers which fall to the floor. The tapping machine produces impact noise at frequencies between 63 Hz and 8,000 Hz.
  • The average unweighted (fast response) sound levels for each octave frequency band between 125 Hz and 4,000 Hz (4KHz) is recorded at ten random locations on the “receiving” (underside) of the floor / ceiling construction for a period of 10 seconds or more.
  • A reverberation time test is also conducted in the “receiving room” and if the room reverberation is not found to be within the nornal criteria, adjustments to the FIIC rating must be made accordingly.
  • The test results are plotted over a family of reference curves, and computations are made to allow for a maximum of 8 dB of deficiencies in any octave band or up to a total of 32 dB of deficiencies in all octave bands combined. The corresponding value of the plot at 500 Hz is the FIIC value.
  • Plot / Print Test Results: We can provide documentation of test results by plotting / printing the test values on paper, and / or provide the results in PDF format.