Finding the Highest 1:1 or 1:3 Octave Band from the Time History Data

It may be useful to find the highest value that occurred in a frequency band during a measurement. As well as the overall Leq in each band, the Optimus/Optimus+ sound level meters store a time history for each frequency band during the measurement and this data can be exported into a spreadsheet for analysis. 

Please note that the data displayed in the time history data is Leq. The overall data rate selected in the Optimus/Optimus+ will affect the number of samples available. To find additional data such as an Lmax within the bands, the Periodic Calculator can be used.

This article explains how to use the Periodic Calculator to produce LMax values within frequency bands.

An example of this would be where it is useful to know not only the overall Leq in each 1:3 octave band but to know the highest point in each of the 31 individual bands.

This article shows how to export the data from NoiseTools.

Once the data has been loaded into Excel, add an additional row at the top of each column above the frequency label and enter into the cells:

=MAX(B3:BXXX) where XXX is the last row of data in the table. In this example shown below, the last row is 12315 so the formula is =MAX(B3:B12315). This will find the highest value within the 8Hz column.

Copy this formula in to each of the cells above the different frequency bands and this will give the highest values in each band.