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