Measuring device for autonomous and wireless detection of fluid media in an environment

A measuring device for detecting at least one property of a fluid medium in an environment, the measuring device comprising:

• at least two electrodes, which are arranged in the environment and spaced from one another, the at least two electrodes configured to measure an electrical capacitance in an intermediate space between the at least two electrodes;
• at least one surface acoustic wave sensor;
• an electrically non-conductive support layer;
• at least one antenna;
• and
• at least one interrogator,
• wherein the at least two electrodes are attached on the electrically non-conductive support layer,
• wherein the at least two electrodes are electrically connected to the at least one surface acoustic wave sensor,
• wherein the at least one antenna is arranged inside the environment and is electrically connected to the at least one interrogator outside the environment by an electrical connection through a feed-through opening through an environment capsule,
• wherein the antenna is configured to transmit a wireless request signal from the at least one interrogator to the at least one surface acoustic wave sensor,
• wherein the at least one surface acoustic wave sensor is configured to be excited by the request signal and the antenna is configured to receive a wireless response signal and transmits the wireless response signal to the at least one interrogator,
• wherein the at least one integrator or a separate evaluation unit is configured to evaluate the wireless response signal in order to measure an electrical capacitance between the at least two electrodes and from a measurement to ascertain at least one property of the fluid medium in the environment.