Free from chattering, AMR sensors have no bounce time. Since they perform an internal sampling, the time required for switching between H and L levels varies depending on the sensor type. Contact bounce is a common problem with mechanical switches and relays made of springy metals. When the contacts strike together, their elasticity may cause them to switch between on and off states (for a short time). Bounce time refers to the duration of this repetitive switching. Long bouncing time may cause mistakes in decision. Microcomputers need to take a certain length of time before deciding that the switch output has changed from H to L or vice versa.