An ultrasonic transducer for an ultrasonic flowmeter includes a transducer housing and a transducer element arranged in the transducer housing for generating and/or receiving ultrasonic signals at least in a useful frequency range of the ultrasonic transducer. The transducer housing has an ultrasound window in the region of the transducer element for transmitting the ultrasound signals between the interior and the exterior of the transducer housing. The transducer housing has a fastening section for fastening the ultrasonic transducer to a measuring tube. The transducer housing extends with a transition section between the ultrasound window and the fastening section. The transition section of the transducer housing has, in an attenuation region, a phononic crystal with an acoustic band gap in the useful frequency range, so that the transmission of ultrasonic signals in the useful frequency range between the ultrasound window and the fastening section is at least attenuated.

An ultrasonic transducer for an ultrasonic flowmeter includes a transducer housing and a transducer element arranged in the transducer housing for generating and/or receiving ultrasonic signals at least in a useful frequency range of the ultrasonic transducer. The transducer housing has an ultrasound window in the region of the transducer element for transmitting the ultrasound signals between the interior and the exterior of the transducer housing. The transducer housing has a fastening section for fastening the ultrasonic transducer to a measuring tube. The transducer housing extends with a transition section between the ultrasound window and the fastening section. The transition section of the transducer housing has, in an attenuation region, a phononic crystal with an acoustic band gap in the useful frequency range, so that the transmission of ultrasonic signals in the useful frequency range between the ultrasound window and the fastening section is at least attenuated.

According to one embodiment, an ultrasonic probe includes a first member and a first vibrating element. The first member includes at least one selected from the group consisting of metal and ceramic. The first vibrating element includes a first electrode, a piezoelectric layer provided between the first electrode and the first member, and a second electrode provided between the piezoelectric layer and the first member and being in contact with the first member.

Methods for noninvasive determination of acoustical properties of flowing in pipes having a large ratio (>10) of pipe diameter to wall thickness, and in highly attenuating fluids are described. When vibrations are excited on the outer surface of the wall of a pipe, the resulting vibrations propagate directly through the wall in a normal direction and through the pipe wall as guided waves, appearing on the opposite side of the pipe. This dual path propagation through pipes, where guided waves take the circumferential path in the wall of the pipe and may interfere with the time of-flight measurement obtained from the direct path through the fluid, is at least in part resolved by subtracting the signal from the guided wave from the combined signal, thereby permitting improved observation of the direct path propagation through the fluid.

Methods for noninvasive determination of acoustical properties of flowing in pipes having a large ratio (>10) of pipe diameter to wall thickness, and in highly attenuating fluids are described. When vibrations are excited on the outer surface of the wall of a pipe, the resulting vibrations propagate directly through the wall in a normal direction and through the pipe wall as guided waves, appearing on the opposite side of the pipe. This dual path propagation through pipes, where guided waves take the circumferential path in the wall of the pipe and may interfere with the time of-flight measurement obtained from the direct path through the fluid, is at least in part resolved by subtracting the signal from the guided wave from the combined signal, thereby permitting improved observation of the direct path propagation through the fluid.

Systems and techniques for measuring process characteristics including electrolyte distribution in a battery cell. A non-destructive method for analyzing a battery cell includes determining acoustic features at two or more locations of the battery cell, the acoustic features based on one or more of acoustic signals travelling through at least one or more portions of the battery cell during one or more points in time or responses to the acoustic signals obtained during one or more points in time, wherein the one or more points in time correspond to one or more stages of electrolyte distribution in the battery cell. One or more characteristics of the battery cell are determined based on the acoustic features at the two or more locations of the battery cell.

A first heat generator heats a mixture of fluids to a first temperature. A predetermined thermal property value of the mixture set to the first temperature is obtained, the first heat generator heats the mixture to a second temperature, the thermal property value of the mixture set to the second temperature is obtained. First relationship information between the thermal property value of the mixture set to the first temperature and a mixture ratio of a first fluid is obtained. Second relationship information between the thermal property value of the mixture set to the second temperature and the mixture ratio of the first fluid is obtained. Mixture ratios are calculated based on the thermal property value of the mixture set to the first temperature, the thermal property value of the mixture of fluids set to the second temperature, the first relationship information, and the second relationship information.

A first heat generator heats a mixture of fluids to a first temperature. A predetermined thermal property value of the mixture set to the first temperature is obtained, the first heat generator heats the mixture to a second temperature, the thermal property value of the mixture set to the second temperature is obtained. First relationship information between the thermal property value of the mixture set to the first temperature and a mixture ratio of a first fluid is obtained. Second relationship information between the thermal property value of the mixture set to the second temperature and the mixture ratio of the first fluid is obtained. Mixture ratios are calculated based on the thermal property value of the mixture set to the first temperature, the thermal property value of the mixture of fluids set to the second temperature, the first relationship information, and the second relationship information.

A gas sensor having a heater, a receiver, and a space arranged between the heater and the receiver, is described, the heater being configured to generate a thermoacoustic sound wave propagating through the space by using a stimulation signal. The receiver is in this case configured to receive the thermoacoustic sound wave that has propagated through the space and to convert it into a reception signal that has a time-of-flight-dependent shift with respect to the stimulation signal and therefore information relating to the gas concentration in the space.

A gas sensor having a heater, a receiver, and a space arranged between the heater and the receiver, is described, the heater being configured to generate a thermoacoustic sound wave propagating through the space by using a stimulation signal. The receiver is in this case configured to receive the thermoacoustic sound wave that has propagated through the space and to convert it into a reception signal that has a time-of-flight-dependent shift with respect to the stimulation signal and therefore information relating to the gas concentration in the space.