The XL2 Acoustic and Audio Analyzer, with the Spectral Limit Option installed, supports these Noise Curve types:
The XL2 measures all noise curve types at the same time, thus you can switch to your required report after the measurement. The result also indicates the frequency band with the highest noise rating between 16 Hz and 8 kHz.
For RNC curve types the XL2 reports any large fluctuations or surging at low frequencies, e.g. caused by fans.
Further following the RNC specification, the XL2 measures the octave-band sound pressure level every 100 ms. The minimum measurement time is 20 seconds.
For curve types NC-2008 and NC-1995, the speech interference level (SIL) result is calculated by averaging the octave-band sound pressure levels at 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz. The XL2 Analyzer includes any tangency method adaptation as applicable.