Progress in Portable Sound level meters with Frequency Analysis - click thumbnails for larger image
On loan from the Acoustics Vibration Unit, UNSW@ADFA

Precision sound level meter and separate filter set with discrete component electronics. Filtering of the signal in each band was undertaken in sequence. Results only on the analogue display and manually recorded Precision sound level meter and separate filter set with analogue integrated electronics. Filtering of the signal in each band was undertaken in sequence. Results only on the screen and manually recorded       Non precision sound level meter with real time display of the frequency spectrum as series of lights and manually recorded Precision sound level meter with digital integrated electronics allowing real time analysis of the signal across the full frequency spectrum. Data stored and downloaded later for analysis