a process fluid sensor for sensing a characteristic of a process fluid is provided . the process fluid sensor includes a metallic sensor body that defines a chamber therein . a piezoelectric crystal element is disposed proximate the chamber and is configured to generate an electrical signal in response to a mechanical input . the piezoelectric crystal element is mechanically coupleable to the process fluid , but is sealed within the sensor body with the exception of a gaseous pathway . a vortex flowmeter utilizing the process fluid sensor is also provided .