A company recently asked us for a LabVIEW expert to write a program for acquiring sound from recreational firearms.
The object was to measure and demonstrate the effectiveness of suppressors. The system contained a PXI system from National Instruments (PXIe-1073 chassis with PXIe-6124 card) together with a specialised microphone and amplifier from G.R.A.S. Sound and Vibration and a laptop fitted with an ExpressCard.
The software performs a triggered acquisition. When a certain (configurable) sound level is exceeded, the sound for a user-defined period before and after that event is displayed and recorded. The user can display the results in Volts, Pascals or (instantaneous) Decibels. Up to 4 firings can be overlaid for comparison in the Results tab. A range of fireams and suppressors are being used in tests.
As we had hoped, the software shows a clear and measurable difference between suppressed and unsuppressed firings. The software development was performed entirely from our office – using TeamViewer to connect to our customer’s system.