Level Type
Measurements include exponential time-weighted average level, Lp, and equivalent level, Leq.
Freq Weighting
Z, A, and C frequency weighting is supported for both Lp and Leq measurements.
Time Weighting (Lp)
Max Levels offers three time
weightings for the Lp sound level measurement: Fast, Slow, and Impulse.
The fast time weighting computes
the exponential-time-weighted average sound level with a time constant of 125 ms. The slow time weighting uses a time constant of 1000 ms, or 1 second. The impulse time weighting uses a rise time constant of 35 ms and a decay time constant of 1500 ms.
Averaging Time (Leq)
Max Levels offers three averaging times
for the Leq sound level measurement: 1/8s, 1s, and ∞.
With 1/8s or 1s, the Leq is calculated over a 1/8 or 1-second time interval, respectively. With ∞, the Leq is calculated over the entire duration of the measurement.
Frequency Range Options
Freq Range Label A/B
A title can be specified for each of the 2 traffic light level indicators in the Max Levels display.
Freq Range Type A/B
For each traffic light level indicator, the level limit type can be set to Overall or Octaves.
Edit Max Level Limits
Tap this item to reveal a spreadsheet-style text grid that allows you to edit separate low (yellow/Warn)
and high (red/Limit)
values for each indicator and for each available frequency band (overall as well as individual
octave bands).
Save Limits As...
To save a copy of the current frequency range limit settings to a file, enter a file name in the text box
and then tap Done on the on-screen keyboard. The new file will be saved in the Max_Levels tool folder within
the app's local Documents directory. The file will include the Freq Range Level and Type settings as well as
all the frequency-dependent limits.
Load Configuration from File
A Max Levels limit settings file (with extension 'mxlim'), created by SignalScope X/Pro or SoundMeter X/Pro,
can be loaded into the Max Levels tool by tapping this option. The file can be loaded from the app's
local files, or browsed for among available document sources on your iOS device (e.g. iCloud Drive,
Dropbox, etc.).
Auto Stop Options
Auto Stop
Max Levels measurements can be configured to automatically stop after a predetermined amount of
time.
Duration
The elapsed time after which the current measurement will stop, or for which sound level data
will be logged, can be set in 1 second increments up to two weeks in duration.
Data Export
Current Location
When exporting Max Levels measurements, you can have the current GPS
coordinates automatically inserted. If you want to have the current location included
automatically, set this switch to "On".