Strutt

Strutt Help



NRC Rating

Strutt|Criteria|Ratings|Absorption|NRC calculates the Noise Reduction Coefficient (NRC) of the current row of the worksheet.

In a 1/3 octave band sheet, the NRC rating is calculated as follows (in accordance with ASTM C634):

`NRC=(alpha_(250)+alpha_(500)+alpha_(1k)+alpha_(2k))/4`, rounded to the nearest 0.05

where:
`alpha_(x)` is the absorption coefficient in each 1/3 octave band.

In an octave band sheet, NRC is calculated as follows (this is NOT in accordance with ASTM C634 and is provided for reference only):

`NRC=(alpha_(250)+alpha_(500)+alpha_(1k)+alpha_(2k))/4`, rounded to the nearest 0.05

where:
`alpha_(x)` is the absorption coefficient in each 1-octave band.


Comments or suggestions to
strutt@arup.com