摘要:
A controller (16) adapted for coupling a plurality of ultrasonic transducers (12, 14) includes a multiplexer (62) for selecting a transducer (12, 14), signal processing means (50) for processing an output of the selected transducer (12, 14), and controller means (64) for providing operational parameters corresponding to the selected transducer (12, 14). The controller (16) couples to a two wire 4-20 mA communication loop (18) to periodically excite the selected transducer (12, 14). The controller (16) stores power received from the communication loop (18) and excites the transducer (12, 14) by using the stored power to exceed the power available directly from the communication loop (18). The controller (16) provides a wet self-test of the transducer (12, 14) whereby the output level of the transducer (12, 14) is monitored while the strength of the excitation signal provided to the transducer (12, 14) is decreased. The amount of decrease required for the output signal to pass a threshold level is an indication of the usefulness of the sensor (18A, 18B-18N).
摘要:
An ultrasonic liquid level sensor (40) inlcudes an ultrasonic coupling element (42) for use in self testing. The sensor (40) includes a gap (20) and a pair of transducers (14, 16) spaced apart by the gap (26). The sensor (40) senses presence of liquid in the gap (20). The ultrasonic coupling element (42) extends between the transducers (14, 16) and acoustically couples them together. The coupling element (42) is used to test ultrasonic sensor integrity.
摘要:
Un système de mesure (14) utilise la rétrodiffusion à neutrons rapides pour mesurer la densité, le niveau et les points de contact des matériaux sensiblement non hydrogénés (18), c'est-à-dire des matériaux autres que ceux contenant de l'hydrogène. On mesure lesdits matériaux (18) dans des cuves (12) à parois épaisses. Le système contient une source de neutrons rapides (16) servant à émettre des neutrons dans le matériau (18) à mesurer. Un système de détection (26) est monté à proximité de la source de neutrons (16), afin de recevoir les neutrons rétrodiffusés. Un système de dégradation d'énergie (22) fait descendre le niveau d'énergie de neutrons rapides jusqu'à une plage de détection souhaitée.
摘要:
A time gate ultrasonic sensor (10) measures a physical property of a material, such as the presence of the material, within a defined space (20). The sensor (10) includes at least one transducer (14, 16) connected to a support structure (12) and positioned generally adjacent the defined space (20) for transmitting and receiving ultrasonic signals (22) across the defined space (20). The ultrasonic signals (22) include a main waveform (48, 62) which travels across the defined space (20) and a self-test waveform (50, 60) which travels along the support structure (18, 43). The sensor (10) monitors the received ultrasonic signals (22) during a main time window (120) to sense whether the main waveform (48, 62) is present in the received signals (22). The sensor (10) senses the physical property of the material within the defined space (20) as a function of whether the main waveform (48, 62) is present within the time window (120).
摘要:
A controller (16) adapted for coupling a plurality of ultrasonic transducers (12, 14) includes a multiplexer (62) for selecting a transducer (12, 14), signal processing means (50) for processing an output of the selected transducer (12, 14), and controller means (64) for providing operational parameters corresponding to the selected transducer (12, 14). The controller (16) couples to a two wire 4-20 mA communication loop (18) to periodically excite the selected transducer (12, 14). The controller (16) stores power received from the communication loop (18) and excites the transducer (12, 14) by using the stored power to exceed the power available directly from the communication loop (18). The controller (16) provides a wet self-test of the transducer (12, 14) whereby the output level of the transducer (12, 14) is monitored while the strength of the excitation signal provided to the transducer (12, 14) is decreased. The amount of decrease required for the output signal to pass a threshold level is an indication of the usefulness of the sensor (18A, 18B-18N).
摘要:
A capacitive level sensor (10) for sensing level of a liquid (102) in a vessel (100) includes a sensor (14) coupled to the vessel (100) having a shield (32) and an inner sensing rod (34). An oscillator (44) provides an RF signal to the shield (32) and the sensing rod (34). Comparison circuitry (48) coupled to the sensing rod (34) provides a wet/dry output in response to capacitance between the inner sensing rod (14) and the vessel (100), the capacitance is related to the level of the liquid (102) in the vessel (100).
摘要:
A controller (16) adapted for coupling a plurality of ultrasonic transducers (12, 14) includes a multiplexer (62) for selecting a transducer (12, 14), signal processing means (50) for processing an output of the selected transducer (12, 14), and controller means (64) for providing operational parameters corresponding to the selected transducer (12, 14). The controller (16) couples to a two wire 4-20 mA communication loop (18) to periodically excite the selected transducer (12, 14). The controller (16) stores power received from the communication loop (18) and excites the transducer (12, 14) by using the stored power to exceed the power available directly from the communication loop (18). The controller (16) provides a wet self-test of the transducer (12, 14) whereby the output level of the transducer (12, 14) is monitored while the strength of the excitation signal provided to the transducer (12, 14) is decreased. The amount of decrease required for the output signal to pass a threshold level is an indication of the usefulness of the sensor (18A, 18B-18N).
摘要:
A capacitive level sensor (10) for sensing level of a liquid (102) in a vessel (100) includes a sensor (14) coupled to the vessel (100) having a shield (32) and an inner sensing rod (34). An oscillator (44) provides an RF signal to the shield (32) and the sensing rod (34). Comparison circuitry (48) coupled to the sensing rod (34) provides a wet/dry output in response to capacitance between the inner sensing rod (14) and the vessel (100), the capacitance is related to the level of the liquid (102) in the vessel (100).
摘要:
Détecteur ultrasonique à sélection temporelle (10) qui mesure une propriété physique d'un matériau, telle que la présence dudit matériau, au sein d'un espace défini (20). Ledit détecteur (10) comporte au moins un transducteur (14, 16) relié à une structure de support (12) et placé généralement dans une position adjacente à l'espace défini (20), en vue de transmettre et de recevoir des signaux ultrasoniques (22) à travers l'espace défini (20). Lesdits signaux ultrasoniques (22) comportent une forme d'onde principale (48, 62) qui parcourt l'espace défini (20) et une forme d'onde d'auto-vérification (50, 60) qui se déplace le long de la structure de support (18, 43). Le capteur (10) contrôle les signaux ultrasoniques reçus (22) pendant une fenêtre temporelle principale (120) pour détecter si la forme d'onde principale (48, 62) est présente dans les signaux reçus (22). Ledit capteur (10) détecte la propriété physique du matériau au sein de l'espace défini (20) en tant que fonction de la présence de la forme d'onde principale (48, 62) dans la fenêtre temporelle (120).