Subway thought they could fool Australians by selling selling us smaller sandwiches. And they got away with it for years because nobody outside of the US or Liberia has any idea what an inch, foot or pound is. But luckily one smart bloke realized it is meant to be 30.5cm and for the next four years, we're all going to get bigger sandwiches. Yay!.
I'm sure the guys in Japan were thinking the same way with their 1" sensor. It sounds pretty big, and 99% of the world wouldn't know better and the other 1% would be thinking, "well..you've got take into account the thickness of the valve housing..." But now that the few dozen of us who have read this thread know that an inch is meant to be 25.4mm, and we've learnt that is way, way bigger than their sensor, I think the game is up. I can see a class action coming.