A shock detector for measuring intermittent shock events comprises a mechanical delay line to supply delayed output motion in response to input motion along an input axis. A transducer converts the delayed output motion to an electrical signal representative of the delayed output motion. The transducer is generally in a respective inactive state to reduce the power consumption of the shock detector. A relatively low power motion sensor, such as low power accelerometer or tilt actuated switch, is employed for switching the transducer to a respective active state in response to the input motion thereby allowing the shock detector to measure any intermittent shock event regardless of the generally inactive state of the transducer.