An accelerometer is an electronic device for detectin' t' presence o' acceleration. Well, blow me down! 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. Blimey! This information can be used t' calculate t' rocket's approximate altitude. An accelerometer can be used t' determine t' proper time for a deployment charge or sustainer motor t' be activated).