Piezoelektrischer Resonator, Verfahren zur Herstellung des Resonators sowie dessen Einsatz als Sensorelement zum Erfassen der Konzentration eines in einem Fluid enthaltenen Stoffes und/oder der Bestimmung physikalischer Eigenschaften des Fluids

Piezoelectric resonator has an electrode region applied on the surface of the resonator and a counter electrode region. A first side of the resonator provides an electrode region electrically connected to an electrode region on the second side of the resonator, on which is provided a counter electrode region electrically insulated from the electrode region. Also claimed is a process for forming a coating on a substrate plate of a resonator. USE - In a sensor element for determining the concentration of a material contained in a fluid or for determining physical properties of a fluid, especially biochemical materials. ADVANTAGE - The resonator is reliable and can be electrically contacted without the danger of short circuits.