Air bag

[nic3c]

At what speed should the air bag inflate on contact?

[gary baldy]

As i understand it - it is not to do with speed but inertia (somebody put me right on this!). You can be standing still and something hits you and (hopefully) the airbag will go off. They are very sophisticated nowadays and they take many readings from various sources to trigger it - speed being just one such source.

[qapmoc]

Hi gb, we don't need to put you right, you already where spot on anyway.

[nic3c]

Thanks. I assume it needs a certain force though...

[gary baldy]

I think when they were first developed they were triggered by by a certain amount of force exerting itself on the actual unit (i suspect a motion sensor ). Nowadays a computer will take sensor readings from all over the car and then 'decides' whether to deploy or not. Some cars even have predictive sensors - analysing your driving and will deploy the airbag milliseconds before you impact. Like i said i think speed is just one part of the equation and i reckon if the conditions are right they will deploy at relatively low speeds (below 30mph).

[KebabMeister]

I left the trade a long time ago but with the early airbags the car had to be doing 10 or 15mph before deployment. Back then they had several sensors around the car but they're all inside the steering wheel now (as well as receiving data from a SRS management system).

[nic3c]

Thanks for all the info!