Leq and time constant problems in Log

[afmpb9574549]

I have two problems in Log.

1: I recorded a time history, A, F, for about 2:20 h. Rew computes the Leq(A) for the all time history = 40.6 dB(A).
I Imported the file in Excel (48976 rows). Calculating the Leq (with VBA routine) I obtain 40.1 dB(A).
The Max and Min levels are correct.
My routine (compared with different Sound Level Meters, professional, Bruel & Kjaer) is correct.
Why this?

2. I used the FAST time constant in REW,
But (IEC standard) The time constant for the FAST is 125 ms, while REW saves data every 170.06 ms.
Is it possible to have the Log file with the correct time constant?

Anf finally, a suggestion.
Would be nice to have the Log file with the story not only of the global levels but also the story of the 1/3 octave spectra (Lin, not A, obviously).
From the spectra is possible to compute every parameter, Leq, Leq(A), percentiles (L10, L90) etc...

Thanks

 

[John Mulcahy]

Calculating the Leq (with VBA routine) I obtain 40.1 dB(A).

Calculated from what, the filtered SPL values? I don't think you can consider those a sufficiently accurate proxy for the accumulated squared magnitudes of the underlying time series.

Is it possible to have the Log file with the correct time constant?

The SPL displays are updated for blocks of 8k samples, logs are updated at the same time. The log interval and the filter time constant are independent of each other.