An accelerometer is an electronic device for detectin' t' presence o' acceleration. An accelerometer can be used for flight data gatherin' or for controllin' flight events. For example, an accelerometer with a memory chip can record t' strength and duration o' a rocket's acceleration. This information can be used t' calculate t' rocket's approximate altitude. Avast, me proud beauty! Blimey! An accelerometer can be used t' determine t' proper time for a deployment charge or sustainer motor t' be activated).