Patent ID: 8850893

Claim:
A sensor for measuring pressure, variation in sound pressure, a magnetic field, acceleration, vibration, or the composition of a gas, said sensor comprising: an ultrasound transmitter, and a cavity arranged in connection with the ultrasound transmitter, which is in resonance mode at the ultrasound frequency used, wherein the sensor comprises a flexible diaphragm, the distance of the flexible diaphragm from the ultrasound transmitter being selected in such a way that the resonance condition is met, the flexible diaphragm being located at the opposite end of the cavity with respect to the ultrasound transmitter, wherein the ultrasound transmitter comprises a diaphragm oscillator, which is connected to a medium around the sensor, wherein the sensor is configured to measure the interaction between the ultrasound transmitter and the cavity, and wherein a reflector cavity is arranged on top of the cavity, in order to increase the sensitivity of the sensor.