3M SE, DL user manual LMn, LMx, Logging, LPk, Octave band, Noise

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Appendix B

LDN

Representing the Day/Night sound level, this measurement is a 24-hour average sound level where 10 dB is added to all of the readings that occur between 10pm and 7am. This is primarily used in community noise regulations where there is a 10 dB “penalty” for night time noise. Typically LDN’s are measured using A weighting, a 3 dB Exchange Rate, and no Threshold.

L_Mn

Minimum SPL. Lowest SPL measured over a time interval.

L_Mx

Maximum SPL. Highest SPL measured over a time interval.

Logging

In sound studies, the saving of measurements at fixed intervals during a study, where each measurement is determined from data processed in the previous logging interval.

L_Pk

Peak SPL. This is the highest SPL value obtained during a study or a session. A peak SPL measurement is affected by the frequency response setting but not by the time response setting of the meter.

Octave band

An Octave band is defined as a frequency band whose upper band-edge frequency is twice the lower band frequency.

Noise

Unwanted sound.

Models SE and DL