3 bar is only a rough approximation of how much positive pressure it will read (with the first bar being atmospheric) it should read to just over 30psi as stated in this thread already.

Im sure SECS will have some useful comments on the subject as he knows far more about his monitor and cossie map sensors than anyone else on the planet does!

Pm him to make sure he notices this thread as the board moves so fast he might miss it other wise.