MEMS based sensors, particularly capacitive sensors, potentially can address critical considerations for users including accuracy, repeatability, long-term stability, ease of calibration, resistance to chemical and physical contaminants, size, packaging, and cost effectiveness. Accordingly, it would be beneficial to exploit MEMS processes that allow for manufacturability and integration of resonator elements into cavities within the MEMS sensor that are at low pressure allowing high quality factor resonators and absolute pressure sensors to be implemented. Embodiments of the invention provide capacitive sensors and MEMS elements that can be implemented directly above silicon CMOS electronics.

A capacitive sensor includes a first electrode structure; a second electrode structure that is counter to the first electrode structure, wherein the second electrode structure is movable relative to the first electrode structure and is capacitively coupled to the first electrode structure to form a capacitor having a capacitance that changes with a change in a distance between the first electrode structure and second electrode structure; a signal generator configured to apply an electrical signal at an input or at an output of the capacitor to induce a voltage transient response at the output of capacitor; and a diagnostic circuit configured to detect a fault in the capacitive sensor by measuring a time constant of the first voltage transient response and detecting the fault based on the time constant and based on whether the first electrical signal is the pull-in signal or the non-pull-in signal.

An apparatus and method for measuring pressure and/or humidity, having at least one sensor for measuring pressure and/or humidity. The sensor has at least one capacitor having at least two electrodes that are arranged in a horizontal direction relative to one another along and on a flexible support material. At least one dielectric layer is arranged between the electrodes. At least one at least partially moisture-permeable and/or moisture-absorbing layer is arranged in some places on a side, facing away from a support material, of the electrode and/or the dielectric layer. The at least one electrode and/or the dielectric layer are arranged transversely between the support material and the moisture layer. In this way, a capacitance is at least partially changed by moisture hitting the dielectric layer, and a processing unit is designed and provided to measure and/or store this change, so as to create a capacitive moisture sensor.

An apparatus and method for measuring pressure and/or humidity, having at least one sensor for measuring pressure and/or humidity. The sensor has at least one capacitor having at least two electrodes that are arranged in a horizontal direction relative to one another along and on a flexible support material. At least one dielectric layer is arranged between the electrodes. At least one at least partially moisture-permeable and/or moisture-absorbing layer is arranged in some places on a side, facing away from a support material, of the electrode and/or the dielectric layer. The at least one electrode and/or the dielectric layer are arranged transversely between the support material and the moisture layer. In this way, a capacitance is at least partially changed by moisture hitting the dielectric layer, and a processing unit is designed and provided to measure and/or store this change, so as to create a capacitive moisture sensor.

An apparatus and a method for measuring pressure, gas and/or humidity, the apparatus having at least one sensor with at least one capacitor comprising at least two electrodes that are arranged in a horizontal direction relative to one another along and on a flexible support material. At least one dielectric layer is arranged between the electrodes and at least one at least partially moisture-permeable and/or moisture-absorbing and/or gas-permeable and/or gas-absorbing moisture layer is arranged at least in some places on a side, facing away from a support material, of at least one electrode and/or the dielectric layer. At least one electrode and/or the dielectric layer are thus arranged transversely between the support material and the moisture layer. A capacitance is at least partially changed by moisture hitting the dielectric layer, and a processing unit measures and/or stores this change, so as to create a capacitive moisture sensor.

An apparatus and a method for measuring pressure, gas and/or humidity, the apparatus having at least one sensor with at least one capacitor comprising at least two electrodes that are arranged in a horizontal direction relative to one another along and on a flexible support material. At least one dielectric layer is arranged between the electrodes and at least one at least partially moisture-permeable and/or moisture-absorbing and/or gas-permeable and/or gas-absorbing moisture layer is arranged at least in some places on a side, facing away from a support material, of at least one electrode and/or the dielectric layer. At least one electrode and/or the dielectric layer are thus arranged transversely between the support material and the moisture layer. A capacitance is at least partially changed by moisture hitting the dielectric layer, and a processing unit measures and/or stores this change, so as to create a capacitive moisture sensor.

A method for correcting a dual-capacitance pressure sensor for measuring fluid pressure, comprising: at a first time, taking measurements of fluid pressure based on movements of a first membrane and a second membrane of the pressure sensor; at a second time, taking measurements of fluid pressure based on movements of the first membrane and the second membrane; determining a change in the measurement results based on movements of the first membrane between the first point in time and the second point in time; determining a change in the measurement results based on movements of the second membrane between the first point in time and the second point in time; Checking whether the changes in the measurements determined are based solely on a change in fluid pressure or whether the changes in the measurements determined are due to changes in the pressure sensor, and if the latter is the case, determining a correction for the measurements determined at the second point in time.

A method for correcting a dual-capacitance pressure sensor for measuring fluid pressure, comprising: at a first time, taking measurements of fluid pressure based on movements of a first membrane and a second membrane of the pressure sensor; at a second time, taking measurements of fluid pressure based on movements of the first membrane and the second membrane; determining a change in the measurement results based on movements of the first membrane between the first point in time and the second point in time; determining a change in the measurement results based on movements of the second membrane between the first point in time and the second point in time; Checking whether the changes in the measurements determined are based solely on a change in fluid pressure or whether the changes in the measurements determined are due to changes in the pressure sensor, and if the latter is the case, determining a correction for the measurements determined at the second point in time.

A method for operating an ultrasonic fluid meter, preferably an ultrasonic water meter, in a fluid distribution network, includes using an ultrasonic transducer to generate an ultrasonic signal which passes through a measurement path, and determining a flow volume by using evaluation electronics on the basis of a transit time and/or a transit time difference of the ultrasonic signal. A hydraulic force change acting on the ultrasonic transducer through the fluid generates a voltage signal waveform on the ultrasonic transducer and the voltage signal waveform is tapped by the evaluation electronics. An ultrasonic fluid meter, preferably ultrasonic water meter, is also provided.

A method for operating an ultrasonic fluid meter, preferably an ultrasonic water meter, in a fluid distribution network, includes using an ultrasonic transducer to generate an ultrasonic signal which passes through a measurement path, and determining a flow volume by using evaluation electronics on the basis of a transit time and/or a transit time difference of the ultrasonic signal. A hydraulic force change acting on the ultrasonic transducer through the fluid generates a voltage signal waveform on the ultrasonic transducer and the voltage signal waveform is tapped by the evaluation electronics. An ultrasonic fluid meter, preferably ultrasonic water meter, is also provided.