Datasheet, page 6:

Other handling precautions

▼That using the wrong pressure range or mounting method may result in accidents.

▼**The only direct pressure medium you can use is dry air**. The use of other media, in particular,
corrosive gases (organic solvent based gases, sulfurous acid based gases, and hydrogen sulfide
based gases, etc.) and **media that contains moisture or foreign substances will cause
malfunction and damage**. Please do not use them. 

EDIT: to make it clear, your device can't work in water and may very well be already dead