A heating value derivation device includes a sound velocity derivation unit configured to derive a sound velocity of a gas flowing through a gas flow path, and a heating value derivation unit configured to refer to correspondence relationship information to derive a heating value per unit volume of the gas.

A measurement system and a method for determining steam quality (i.e. vapor mass fraction) measurements of multi-phase fluid flowing through pipes are described. An acoustic sensor device consists of an acoustic transmitter and an acoustic receiver that are designed to be attached to a pipe. The acoustic transmitter and the acoustic receiver are exposed to an interior space of the pipe through openings in a wall of the pipe. Acoustic waves generated by the transmitter and captured by the receiver traverse the multi-phase fluid flowing into the pipe. Swept-frequency acoustic interferometry (SFAI) technique is used to measure ultrasonic acoustic properties of a fluid. Machine-learning techniques based on principal component analysis, support vector machine regression and support vector machine classification are used for determining steam quality.

An electric measurement circuit possesses an electrical reaction leg for forming an oscillator from a resonator, and furthermore possesses a measurement leg the input of which is supplied by the electrical reaction leg. The measurement leg contains an adjustable phase shifter so that an additional excitation force that is applied to the resonator in the measurement leg can be adjusted in phase quadrature with respect to an excitation force that is applied to the resonator in the electrical reaction leg. Such an electrical measurement circuit is particularly suitable for forming a photoacoustic gas detector.

The present disclosure relates to a probe structure that includes a probe configured to transmit or receive acoustic energy and having a first end and a second end opposite the first end, a probe hub defining a cavity for receiving at least a portion of the probe, and a joint coupled to the second end of the probe and configured to allow the probe to pivot within the probe hub.

In accordance with an embodiment, a MEMS sensor includes a membrane that is suspended from the substrate, a resonant frequency of said membrane being influenced by an ambient pressure that acts on the membrane; and an evaluation device configured to perform a first measurement based on the resonant frequency of the membrane to obtain a measurement result, where the evaluation device is configured to at least partly compensate an influence of the ambient pressure on the measurement result

A method includes receiving a gas or gas mixture through a flow sensor. A flow velocity, volumetric, or mass flow are determined. The method also includes determining a sound velocity of the gas or gas mixture by an ultrasonic sensor. A density of the gas or gas mixture is correlated from the sound velocity. The method also includes positioning a microthermal sensor in an area with less flow or no flow of the gas or gas mixture. A thermal conductivity and thermal diffusivity of the gas or gas mixture at the one or more temperatures is determined. The method also includes connecting a processor to the microthermal sensor to calculate an energy of the gas or gas mixture based on a calorific value, the temperature and the volume or mass flow. Specific quantities for gas quality are correlated.

A heating value derivation device and a heating value derivation method. A gas meter as a heating value derivation device includes a sound velocity derivation unit configured to derive a sound velocity of a gas flowing through a gas flow path, a heating value derivation unit configured to refer to correspondence relationship information that enables a heating value per unit volume to be uniquely derived from the sound velocity of the gas, to thereby derive the heating value per unit volume of the gas, which is independent of a type of the gas, based on the sound velocity derived by the sound velocity derivation unit, and a flow rate derivation unit configured to derive a flow rate of the gas that has passed through the gas flow path. Thus, a passage heating value of the gas can be derived.

Provided is a gravity compensation control device including a first mounting unit, a rotatable link, one end of which is connected to a compensation shaft arranged in the first mounting unit and another end of which is vertically movable by a weight applied thereto, wherein a portion between the ends is supported by a fixed shaft arranged in the first mounting unit, such that the link is rotatable about the fixed shaft, and a weight compensation device, wherein the weight compensation device includes a bearing unit including a bearing shaft arranged in the first mounting unit, and a bearing coupled to the bearing shaft, an auxiliary link connected to the compensation shaft and one side of the bearing unit, and an elastic member coupled to another side of the bearing unit and arranged in a lengthwise direction of the auxiliary link.

The present invention relates to system for measuring pressure and temperature based on change in the characteristic properties of a medium for ultrasound under the effect of pressure and temperature. The invention is based on two waveguides where geometry is adapted to the medium's characteristic properties for ultrasound such that only planar pressure waves are generated in the waveguides. The first of the waveguides is arranged for measuring temperature due to thermal expansion of the medium, where the medium is pressure-compensated by means of an internal compensator to prevent thermal pressure accumulation, and where measuring temperature is based on the medium's specific known characteristic data for ultrasound under the effect of temperature under constant pressure. The second waveguide is arranged for measuring pressure, based on waveguide and the medium's known characteristic properties for thermal expansion and pressure, and where the thermal effect is corrected analytically based on measurement of temperature in the first channel. The physical principle of the invention is based on the properties of a medium (oil) where the stability for high temperature and pressure is crucial for long-term properties. Long-term properties of ultrasound sensors are not physically linked to the medium's properties, such that change in characteristic properties of ultrasound sensors does not impair the accuracy of the medium unless the function of the ultrasound sensors ceases. The physical principle of the invention allows an arrangement where ultrasound sensors can be separated from measuring channels by a pressure barrier, such that the integrity of the pressure barrier is not broken.

There is presented a device for being secured to a structure. The device comprising a first portion comprising an element configured to impart mechanical waves to the structure upon application of a voltage and a second portion supporting the element and comprising a body. The body may be elastomeric, flexible, or both. The first and second portions are configured such that the element reacts against the second portion to generate mechanical waves at least partially within the structure. The body attenuates mechanical waves propagating from the first portion and away from the structure. A securing device for securing a mechanical wave generator to a structure and a system comprising the securing device are also presented.