Shock sensors that detect only a STRONG impact or can be set to?

Hey everyone! I'm looking for a crash sensor that can detect a strong impact or can be programmed to only detect an impact at a certain level of severity? I'm trying to find one that will set off an alarm via my arduino, but not because of every little bump. I only want it to go off at a certain level of impact. Thank you!

The ADXL377 is intended as a crash sensor (200 g range).

jremington:
The ADXL377 is intended as a crash sensor (200 g range).

I thought the ADXL types were accelerometers? Do you have a place I can look up on how to use it as a shock sensor? Thanks!

Ian_McElrath:
I thought the ADXL types were accelerometers? Do you have a place I can look up on how to use it as a shock sensor? Thanks!

The Wikipedia page for "shock" says, "A mechanical or physical shock is a sudden acceleration..."

Monitor the acceleration at regular intervals and calculate the change with respect to time. Compare each calculated value against whatever threshold you define as a "Strong impact".

Sensors like the ADXL377 were originally developed to deploy air bags during car crashes. The ADXL377 is a bit more general, and the data sheet suggests the following applications:

APPLICATIONS
Concussion and head trauma detection
High force event detection

Many high-g accelerometers feature an interrupt when a user-adjustable acceleration level is achieved, so you don't have to monitor the sensor values constantly. Here is a selection table for those from Analog Devices. There are several other manufacturers of suitable accelerometers.