Field device for determining and/or monitoring a process variable

A field device for determining and/or monitoring at least one process variable of a medium in a container, comprising:

• at least one mechanically oscillatable unit connected with the container via a process connection, said mechanically oscillatable unit has at least three oscillatory members;
• at least one oscillatory member is connected, at an attachment region, with the process connection;
• and
• at least one driver/receiver unit, wherein:
• said driver/receiver unit excites said mechanically oscillatable unit to oscillate, and/or said driver/receiver unit detects the oscillations of said mechanically oscillatable unit;
• said three oscillatory members execute oscillations, which said driver/receiver unit produces, and/or detects;
• said three oscillatory members comprise a long rod of length (L), mass (M) and stiffness (EI), a first short rod of length (L1), mass (M1) and stiffness (EI1) and a second short rod of length (L2), mass (M2) and stiffness (EI2);
• said first short rod is connected, with an end region turned toward the process, to said long rod, at an end region of said long rod turned toward the process;
• said second short rod is connected, with an end region turned away from the process, to said long rod, at an end region of said long rod turned away from the process;
• and said long rod is connected with the process connection at least at an attachment region;
• and
• said three oscillatory members are embodied and interconnected in such a manner, and said attachment region is selected in such a manner, that an approximately defined transmission of reaction forces and reaction torques occurs between said mechanically oscillatable unit and the process connection.