A transducer modulus, comprising: a supporting substrate; a cap, which is arranged on the supporting substrate and defines a chamber therewith; a pressure transducer in the chamber; an acoustic transducer in the chamber; and a processing chip, or ASIC, operatively coupled to the pressure transducer and to the acoustic transducer. The pressure transducer and the acoustic transducer are arranged on top of one another to form a stack.

Disclosed herein is a carbonated water producing apparatus which guides a replacement of a cylinder using sound generated when carbon dioxide is supplied from the cylinder, and a refrigerator having the same. In accordance with one aspect of the present disclosure, a carbonated water producing apparatus comprising: a carbonated water producing unit including a cylinder configured to store carbon dioxide and configured to supply the carbon dioxide to a container; a microphone configured to obtain sound generated in the carbonated water producing unit; a filter configured to pass a signal having a frequency of a predetermined cutoff frequency or more of signals obtained by the microphone; a user interface unit configured to display information related to carbonated water production; and a controller configured to obtain the sound generated in the carbonated water producing unit by driving the microphone when the carbonated water producing unit operates, and configured to display a message which requests that the cylinder which stores the carbon dioxide be replaced on the user interface unit when an intensity of a signal passing through the filter is less than a predetermined reference value.

A method and system of the invention generally relate to measuring ambient pressure in systems comprising incompressible fluids. Particularly, the method and system relate to monitoring pressure within body lumens. The ambient pressure may be measured by transmitting a frequency comb having non-uniform spacing between transmitted frequencies at the passive sensor and measuring the frequency response of the passive sensor. In one embodiment, a higher-order harmonic of the sensor is excited and measured to determine the ambient pressure. In another embodiment, the frequency response of frequencies in-between the transmitted frequencies are measured to determine the ambient pressure.

A method and system of the invention generally relate to measuring ambient pressure in systems comprising incompressible fluids. Particularly, the method and system relate to monitoring pressure within body lumens. The ambient pressure may be measured by transmitting a frequency comb having non-uniform spacing between transmitted frequencies at the passive sensor and measuring the frequency response of the passive sensor. In one embodiment, a higher-order harmonic of the sensor is excited and measured to determine the ambient pressure. In another embodiment, the frequency response of frequencies in-between the transmitted frequencies are measured to determine the ambient pressure.

A method for determining concentration and pressure of respective gas consisting of multi-gas using emitting and receiving of ultrasound includes: measuring a reference ultrasound flight time; measuring ultrasound flight times at plural concentrations, temperatures and pressures; obtaining an ultrasound flight time table comprising ultrasound flight time change values which are differences between the reference ultrasound flight time, which varies according to parameters of concentration, temperature and pressure, and the measured ultrasound flight time; obtaining an ultrasound amplitude table comprising ultrasound amplitude values of a waveform of a predetermined sequence of the received ultrasound waveform at plural concentrations, temperatures and pressures in a state that concentration, temperature and pressure of the target respective gas are parameters; and calculating the concentration and the pressure of the target gas based on performing temperature compensations for the ultrasound flight time change values and the ultrasound amplitude values.

A method for determining concentration and pressure of respective gas consisting of multi-gas using emitting and receiving of ultrasound includes: measuring a reference ultrasound flight time; measuring ultrasound flight times at plural concentrations, temperatures and pressures; obtaining an ultrasound flight time table comprising ultrasound flight time change values which are differences between the reference ultrasound flight time, which varies according to parameters of concentration, temperature and pressure, and the measured ultrasound flight time; obtaining an ultrasound amplitude table comprising ultrasound amplitude values of a waveform of a predetermined sequence of the received ultrasound waveform at plural concentrations, temperatures and pressures in a state that concentration, temperature and pressure of the target respective gas are parameters; and calculating the concentration and the pressure of the target gas based on performing temperature compensations for the ultrasound flight time change values and the ultrasound amplitude values.

An environmental condition may be measured with a sensor (10) including a wire (20) having an ultrasonic signal transmission characteristic that varies in response to the environmental condition by sensing ultrasonic energy propagated through the wire using multiple types of propagation, and separating an effect of temperature on the wire from an effect of strain on the wire using the sensed ultrasonic energy propagated through the wire using the multiple types of propagation. A positive feedback loop may be used to excite the wire such that strain in the wire is based upon a sensed resonant frequency, while a square wave with a controlled duty cycle may be used to excite the wire at multiple excitation frequencies. A phase matched cone (200, 210) may be used to couple ultrasonic energy between a waveguide wire (202, 212) and a transducer (204, 214).

An environmental condition may be measured with a sensor (10) including a wire (20) having an ultrasonic signal transmission characteristic that varies in response to the environmental condition by sensing ultrasonic energy propagated through the wire using multiple types of propagation, and separating an effect of temperature on the wire from an effect of strain on the wire using the sensed ultrasonic energy propagated through the wire using the multiple types of propagation. A positive feedback loop may be used to excite the wire such that strain in the wire is based upon a sensed resonant frequency, while a square wave with a controlled duty cycle may be used to excite the wire at multiple excitation frequencies. A phase matched cone (200, 210) may be used to couple ultrasonic energy between a waveguide wire (202, 212) and a transducer (204, 214).

A method of measuring a pressure of a fluid adjacent a wall of a pipe or vessel. A transducer is attached to the wall of the pipe or vessel. A signal is transmitted by the transducer at a characteristic frequency via a plurality of guided wave modes. The characteristic frequency is a frequency at which the guided wave modes are separated in time from each other when received. The signal is received after the plurality of guided wave modes travel in or through the wall a predetermined number of times. The signal has a signal receipt time after the predetermined number of times. The pressure of the fluid is calculated using the signal receipt time.

A method of measuring a pressure of a fluid adjacent a wall of a pipe or vessel. A transducer is attached to the wall of the pipe or vessel. A signal is transmitted by the transducer at a characteristic frequency via a plurality of guided wave modes. The characteristic frequency is a frequency at which the guided wave modes are separated in time from each other when received. The signal is received after the plurality of guided wave modes travel in or through the wall a predetermined number of times. The signal has a signal receipt time after the predetermined number of times. The pressure of the fluid is calculated using the signal receipt time.