Inside Out Library · Explore
A Sound Pressure-level Meter Without Amplification (1937)
NASA Technical Reports Server (NTRS) · leaf 6
Figs.,3, N.A.C.A. Technical Note No.629 if … Figure 3.- Pressure-level meter with band-pass filters connected.NASA Technical Reports Server (NTRS)
Internet Archive · NASA Technical Reports · Public domain (US government work). Free to use for anything.
More pictures from A Sound Pressure-level Meter Without Amplification
More like this
