NTi's XL2 Audio and Acoustic handheld analyser can now provide on-site results of the Room Noise Criterion (RNC).
Room Noise Criterion measurements are recommended if the ambient noise contains modulated or fluctuating noise components in the low frequency range, such as those generated by HVAC systems.
The XL2 measures the octave-band sound pressure level to determine the applicable room noise criterion (RNC) curve in accordance with the ANSI 12.2-2008 standard.
The instrument averages the acoustic spectrum every 100 ms and monitors for any low frequency fluctuation. If the measurement results exceed the limits for non-fluctuations then the LEQ levels below 300 Hz are “penalisedâ€.