English to Italian Tech/Engineering Transport / Transportation / Shipping Train -

Paragraph talking about "random parameters" such as average XX frames parameter, gain parameter, slew rate parameter..

The Clipping XX Sigma parameter adjusts the allowable peak output level relative to the RMS output level. Since the output signal is random, it will typically have an occasional high peak value.
The sigma clipping level limits the amplitude of these peaks and is typically used to prevent over-voltage tripping of the amplifier input and to limit the peak displacement value required by tests.