Passenger side air bag deployment ?

[Potomac Pat]

Just trying to figure something out. In regards to late model Mercedes Benz passenger side air bags. Where is the sensor located that allows the bag to deploy on the passenger side? Does it work in conjunction w/ a signal from the seat belt harness as well. I have been told that there is a sensor mounted in the seat that is activated by the amount of weight and/or pressure that exists during an accident? Any ideas?????