Abstract: A differential pressure sensor having a vent to atmosphere and mounted where it is subject to water spray has a vent cap which protects against spray entering the vent and prohibits water residing along the cap edges from being drawn into the vent. The vent is surrounded by an upstanding collar and the vent cap snaps onto the collar. A shroud extends laterally from one side of the cap to a point beyond the sensor package and further extends down below the upper surface of the package. The shroud is open at the bottom to afford an air passage to the vent as well as a baffle against spray.