The XL2 Acoustic Analyzer measures the background noise spectrum of the unoccupied room in accordance with the standard. The resulting frequency spectrum gets classified by the Noise Curves. The noise rating is designated as the value of the highest noise curve “touched” by the measured noise spectrum in 1 dB steps.
This allows a quick verification if the background noise in the room under test meets the specified requirements and shall not annoy people occupying the room. The Noise Curve functionality is optional and requires that the Spectral Limits Option be installed on the instrument.
The XL2 indicates the frequency band with the highest noise curve rating between 16 Hz and 8 kHz. Additionally, the instrument calculates also the speech interference level (SIL) result by averaging the octave-band sound pressure levels at 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz.
The XL2 Acoustic Analyzer measures the following Noise Curves:
- Noise Criteria NC (ANSI/ASA S12.2-2019)
- Room Noise Criterion RNC (ANSI/ASA S12.2-2019)
- Room Criteria RC (ANSI/ASA S12.2-2019)
- Noise Rating NR (ISO/R 1996-1971)
- PNC Rating (ASA 1971)