Strutt|Criteria|Curves|Sound Levels|NR inserts the Noise Rating (NR) curve into the active row of the worksheet. The user may enter the curve number into Column D of the active row to return a specific NR curve.
The NR curve is defined for integer curve numbers, and is calculated from the following formula:
`NR = A + B(NR#)`, where `NR#` is the curve number
and `A` and `B` are frequency-dependent coefficients defined as:
|Frequency||31.5 Hz||63 Hz||125 Hz||250 Hz||500 Hz||1 kHz||2 kHz||4 kHz||8 kHz|
Note: Strutt rounds each curve value to 1 decimal place, using the `A` and `B` values above as defined in the standard