Abrégé

Properties of a medium, such as its particle size distribution, are characterized using a measurement cell containing a medium between walls of the cell, with ultrasound transducers on opposite walls. Ultrasound is transmitted from the ultrasound transducers on both sides and transmission and reflection responses are detected. An ultrasound frequency dependent ratio of a Fourier transform value of a product of signals obtained from transmission responses in opposite directions and a Fourier transform value of a product of signals obtained from reflections at the transducers is computed. Preferably, the first received reflected and transmitted pulses in response to pulse excitation are used to compute the ratio. Ultrasound frequency dependent ultrasound speed and/or attenuation data of ultrasound in the medium are computed as a function of the ultrasound frequency from the ratio. This eliminates the effect of the walls.

Classes IPC  ?

• G01N 29/52 - Traitement du signal de réponse détecté en utilisant des procédés d'inversion autres que l'analyse spectrale, p. ex. inversion conjuguée de gradient
• G01N 29/46 - Traitement du signal de réponse détecté par analyse spectrale, p. ex. par analyse de Fourier
• G01N 29/032 - Analyse de fluides en mesurant l'atténuation des ondes acoustiques
• G01N 29/024 - Analyse de fluides en mesurant la vitesse de propagation ou le temps de propagation des ondes acoustiques
• G01N 29/34 - Génération des ondes ultrasonores, sonores ou infrasonores
• G01N 29/44 - Traitement du signal de réponse détecté
• G01N 15/02 - Recherche de la dimension ou de la distribution des dimensions des particules

Abrégé

Properties of a medium, such as its particle size distribution, are characterized using a measurement cell containing a medium between walls of the cell, with ultrasound transducers on opposite walls. Ultrasound is transmitted from the ultrasound transducers on both sides and transmission and reflection responses are detected. An ultrasound frequency dependent ratio of a Fourier transform value of a product of signals obtained from transmission responses in opposite directions and a Fourier transform value of a product of signals obtained from reflections at the transducers is computed. Preferably, the first received reflected and transmitted pulses in response to pulse excitation are used to compute the ratio. Ultrasound frequency dependent ultrasound speed and/or attenuation data of ultrasound in the medium are computed as a function of the ultrasound frequency from the ratio. This eliminates the effect of the walls.

Classes IPC  ?

• G01N 25/02 - Recherche ou analyse des matériaux par l'utilisation de moyens thermiques en recherchant les changements d'état ou de phaseRecherche ou analyse des matériaux par l'utilisation de moyens thermiques en recherchant le frittage
• G01N 29/024 - Analyse de fluides en mesurant la vitesse de propagation ou le temps de propagation des ondes acoustiques
• G01N 29/032 - Analyse de fluides en mesurant l'atténuation des ondes acoustiques
• G01N 29/46 - Traitement du signal de réponse détecté par analyse spectrale, p. ex. par analyse de Fourier
• G01N 29/52 - Traitement du signal de réponse détecté en utilisant des procédés d'inversion autres que l'analyse spectrale, p. ex. inversion conjuguée de gradient
• G01N 29/34 - Génération des ondes ultrasonores, sonores ou infrasonores