Mounting an accelerometer on the source pistol gives precise shot timing for impulse tests.

Evidence

A 0.45 caliber pistol fired hand-loaded, black powder blanks to produce a loud impulse that was recorded by sensors placed at known locations in the forest. The pistol was held 1 m above the snow or ground surface, pointed towards the sensors, and fired to initiate a measurement. We mounted a small accelerometer directly on the pistol and connected it to the digital recorder; the accelerometer signals were used to start the recording and to determine the firing time. — Donald G. Albert, Michelle E. Swearingen, Frank E. Perron, and David L. Carbee, Low Frequency Acoustic Pulse…, 53

Categorization

• SHARE: The image of geophysicists firing a black-powder .45 into a snow-covered forest to time acoustic arrivals is exactly the sort of tidbit a field-seismology friend would love.
• CANDY: A hand-loaded .45 firing blanks at the snow as a controlled acoustic source is instantly retellable.