Hello. I am designing a housing for a pressure sensor and I am a bit confused. Some places on the internet O-ring squeeze ratio is expressed as the amount of o-ring squeeze divided by the o-ring cross section. Other places it is expressed as the amount of squeeze divided by groove depth. These two methods of calculation give very different answers. My O-ring is 1.778mm thick and the groove is 1.325mm deep. The first method gives a squeeze ratio of 25.5%, the other 34%. Which of these is the correct way?