摘要:
In a method for the transmission of an acoustic signal to a microphone in a photoacoustic cell being part of an apparatus for photoacoustic analysis of substances or gases and in which the zone (40) containing a medium to be analysed represents a damaging environment to the microphone (10), the latter is connected to an excitation zone (30) through a waveguide (20) into which a protecting gas which is chemically neutral to the medium sample has been introduced between the microphone (10) and the medium to prevent the medium from reaching the microphone, the protecting gas being furthermore of a type which allows the waveguide (20) to transmit the acoustic signal generated in the medium through the protecting gas to the microphone without any significant weakening of the signal.
摘要:
L'invention a pour objet un procédé de contrôle du contact de deux tôles placées bord à bord dans lequel, on émet un signal ultrasonore se propageant dans une des deux tôles (1, 2), ledit signal ultrasonore traversant le plan de joint (3) desdites tôles sur toute sa hauteur et se propageant par la seconde tôle (2), on capte ledit signal ultrasonore dans la seconde tôle (2) et on détermine la qualité du contact des tôles (1, 2) au niveau du plan de joint (3) en comparant ledit signal ultrasonore capté par rapport audit signal ultrasonore émis. L'invention a également pour objet un dispositif de contrôle pour la mise en oeuvre de ce procédé.
摘要:
L'invention se rapporte principalement à un dispositif et à un procédé de détection de changement de phases et de caractérisation de la phase d'un produit liquide, gélifié ou solide à son contact ou à travers son contenant. L'invention a pour objet un procédé de détection d'un changement de phases et/ou de caractérisation de la phase d'un produit (16) comportant une étape d'insonification du produit avec des ondes ultrasonores et une étape de réception du rayonnement acoustique du produit insonifié, caractérisé en ce qu'il comporte les étapes consistant à :
disposer le transducteur d'émission/réception ou le transducteur d'émission et le transducteur de réception à l'extérieur d'un contenant du produit à étudier ; assurer un couplage acoustique entre le ou les transducteurs et le produit à étudier ; analyser le signal reçu et le comparer à un modèle ; en déduire la phase ou le mélange de phases du produit.
L'invention s'applique à toute industrie nécessitant la caractérisation ou la mesure de la texture, et notamment à l'industrie alimentaire, pharmaceutique, cosmétologique, plastique et aux industries de peinture. L'invention s'applique particulièrement à la fabrication de fromages.
摘要:
A method of testing a container for corrosion, comprising the steps of applying a signal in the range 30kHz - 100kHz to said container and monitoring the attenuation of said signal in said container. The method is particularly useful for testing cylinders in packs without the need to dismantle the pack.
摘要:
A method for ( in situ ) measuring a sample of an air-permeable material having a fine granular material located within its pores eg toner in a 2 component developer and, in particular, for determining the concentration of the fine granular material within the sample includes the steps of transmitting an acoustic slow wave of known amplitude and phase velocity, through the sample, detecting the attenuation and/or propagation velocity of the wave after passage through the sample, and determining the concentration of the fine granular material in the sample from the changes in the acoustic signal. The apparatus uses two acoustic transducers (86,88) with the sample between them. In a second method changes in the resonant frequency of an acoustic transducer (98) immersed in the sample are used to monitor changes in the acoustic impedance of the sample and thus the toner concentration.
摘要:
The strength of a join between a ceramic and an associated non-ceramic is determined using an ultrasonic microscope. A converging ultrasonic beam (B) is radiated against a point (P) on a surface of the ceramic (1), said point being a predetermined distance away from the join (3) between the ceramic (1) and the associated non-ceramic (2). Data on the intensities of interference waves at respective predetermined variations of the relative distance between a probe (5) of the ultrasonic microscope and the ceramic (1) are collected. The residual stress at the point is calculated on the basis of the cycle of echo intensities of the interference waves for the respective predetermined variations of the relative distance. The strength of the join is then determined on the basis the residual stress.
摘要:
Die Erfindung betrifft ein Verfahren und eine Mess- und Auswerteeinrichtung (21) zur Ermittlung von Defekten in einer Turbinenschaufel (7) sowie eine Fixiervorrichtung (14) zum Fixieren eines Prüfkopfes (18) an eine Turbinenschaufeloberfläche (13).
摘要:
A system for inspecting adhesive in a composite structure, such as for soft or improperly cured regions, includes a transducer and a processing element. The transducer can transmit a signal, such as an ultrasonic signal, into the adhesive such that at least a portion of the ultrasonic signal can propagate through the adhesive, reflect off of an interface between the adhesive and another material, and propagate back through the adhesive. Upon exiting the adhesive, then, the transducer can receive a reflected portion of the ultrasonic signal. Thereafter, the processing element can identify a defect, such as soft or improperly cured regions, in the adhesive upon a relationship of an amplitude of the reflected portion of the reflected ultrasonic signal to a predefined threshold.
摘要:
The invention relates to a method for the non-destructive testing of a welded joint of a stud (8) welded onto a planar sheet metal (6) in a contact area (4), especially of a stud bolt welded according to a drawn arc welding method. According to the inventive method, a weld pool (10) having a modified material structure is formed in the sheet metal below the contact area (4). The inventive method uses directed ultrasound signals and comprises the following process steps: subjecting the sheet metal (6) to ultrasound signals by means of a directed ultrasound emitter (1) that emits the signals at an angle in a site of coupling-in (A); coupling out the ultrasound signals transmitted through the sheet metal (6) in a site of coupling-out (B) by means of an ultrasound receiver (2), whereby the site of coupling-out (B) is located in the sound propagation path of undisturbed signal propagation of the emitted ultrasound signals in the sheet metal (6), the sound propagation path in the sheet metal (6) extending between the site of coupling-in (A) and the site of coupling-out (B) in such a distance to the contact area (4) that the weld pool (10) of a weld joint to be classified as intact is covered by the sound propagation path of the ultrasound signals; and detecting the intensity of the ultrasound signals transmitted from the site of coupling-in (A) to the site of coupling-out (B).