Abstract: A SAW sensor arrangement includes a transducer including a support for supporting a SAW device. The support includes a sensor location part located between two oppositely extending attachment parts. The SAW device is mountable to the sensor location part. The sensor arrangement 10 includes at least two spaced friction raisers. The sensor arrangement includes a clamp arrangement which applies a clamping force to clamp the sensor arrangement to an item. The sensor arrangement is arranged so that in use each of the friction raisers is located between a different one of the attachment parts and the item.

Abstract: A SAW sensor arrangement includes a transducer including a support for supporting a SAW device. The support includes a sensor location part located between two oppositely extending attachment parts. The SAW device is mountable to the sensor location part. The sensor arrangement 10 includes at least two spaced friction raisers. The sensor arrangement includes a clamp arrangement which applies a clamping force to clamp the sensor arrangement to an item. The sensor arrangement is arranged so that in use each of the friction raisers is located between a different one of the attachment parts and the item.

Abstract: A circular shaft having a platform formed on it by machining a circular flat into the surface of the shaft. A channel extends around the periphery of the circular flat with a depth in the range of 10 to 15% of the diameter of the shaft and in the range of 30 to 50% of the width/diameter of the platform. The width of the platform is 4 to 7% of the diameter of the shaft. A sensor is mounted on the platform, whereby the formation of the platform and surrounding channel reduces the strain arising in the device which is transferred to the sensor.

Abstract: Aspects of the present invention are directed to using surface acoustic wave (SAW) sensors mounted on a disc coupling component in a powertrain to measure the torque generated by an automobile engine. The sensor may be positioned and oriented on the disc coupling component so that the phase velocities of SAWs propagating through active elements of the SAW sensors are aligned with principal strain components due to torque in the disc coupling component. The torque may be calculated by determining the difference between resonant frequencies of the active elements to suppress common-mode interference factors. In addition, SAW resonant frequencies may be communicated in a non-contacting manner by utilizing rotary and stationary couplers employing radio frequency (RF) signals. Moreover, SAW sensors may be activated and interrogated by employing targeted RF pulses having different carrier frequencies at or near respective resonant frequencies of each resonator in a SAW sensor.

Abstract: A method is provided for measuring torque in a shaft of a drive line including a disc coupling component such as a flexplate 1 or a flanged coupling 13, as well as a drive coupling system for carrying out the method. The disc coupling component 1, 13 is connected between a drive input 4 and a drive output so that all torque transmitted between the input and output passes through said component. The disc coupling component 1, 13 has a radially extending portion, which may include a plurality of spokes 7, to which is attached a SAW based strain sensor which communicates with a stationary coupler 3 fastened to an engine block 5 for wireless transmission of data from the sensor, the strain sensor measuring the strain in the disc coupling component 1, 13 from which the torque carried in the input shaft 4 may be calculated.

Abstract: A circular shaft having a platform formed on it by machining a circular flat into the surface of the shaft. A channel extends around the periphery of the circular flat with a depth in the range of 10 to 15% of the diameter of the shaft and in the range of 30 to 50% of the width/diameter of the platform. The width of the platform is 4 to 7% of the diameter of the shaft. A sensor is mounted on the platform, whereby the formation of the platform and surrounding channel reduces the strain arising in the device which is transferred to the sensor.

Abstract: Aspects of the present invention are directed to using surface acoustic wave (SAW) sensors mounted on a disc coupling component in a powertrain to measure the torque generated by an automobile engine. The sensor may be positioned and oriented on the disc coupling component so that the phase velocities of SAWs propagating through active elements of the SAW sensors are aligned with principal strain components due to torque in the disc coupling component. The torque may be calculated by determining the difference between resonant frequencies of the active elements to suppress common-mode interference factors. In addition, SAW resonant frequencies may be communicated in a non-contacting manner by utilizing rotary and stationary couplers employing radio frequency (RF) signals. Moreover, SAW sensors may be activated and interrogated by employing targeted RF pulses having different carrier frequencies at or near respective resonant frequencies of each resonator in a SAW sensor.

Abstract: An apparatus 1 for packaging a sensor device comprises a main body 2 having an internal chamber 4 with a base 2b on which, in use, is mounted the sensor so as to couple the sensor to the strain field in an article to which the packaging is attached by means of said base. A lid 3 is separately formed from and is formed of a different material to said base 2b and is sealable to the main body 2 in order to seal close said internal aperture 4. The lid 3 includes contact pins 8, 9 which extend therethrough from one side to the other. A first end 8a, 8b of each said pin 8, 9 extends into said chamber 4 when the lid 3 is positioned on the body 2 for connection to said sensor and a second end 8b, 9b of each said pin 8, 9 extends away from the package when the lid 3 is positioned on the body 2 for connection to a rotary coupler.

Abstract: A method is provided for measuring torque in a shaft of a drive line including a disc coupling component such as a flexplate 1 or a flanged coupling 13, as well as a drive coupling system for carrying out the method. The disc coupling component 1, 13 is connected between a drive input 4 and a drive output so that all torque transmitted between the input and output passes through said component. The disc coupling component 1, 13 has a radially extending portion, which may include a plurality of spokes 7, to which is attached a SAW based strain sensor which communicates with a stationary coupler 3 fastened to an engine block 5 for wireless transmission of data from the sensor, the strain sensor measuring the strain in the disc coupling component 1, 13 from which the torque carried in the input shaft 4 may be calculated.

Abstract: A SAW based sensor having a base and a lid engageable with the base to form an internal cavity therewith. A substrate is supported in the cavity on either tile base or the lid 13 and a dimple 16 is formed on the other which extends towards the substrate so as to engage against the substrate and apply a preload thereto. The base and lid include complementary threads by means of which they are attachable to each other. The preload applied to the substrate by the dimple 16 is adjustable by varying the rotational position of the lid relative to the base.

Abstract: A pressure monitor has a base and a lid secured to the base to define a substantially fluid tight chamber. At least part of the lid is flexible and forms a diaphragm which deflects responsive to changes in fluid pressure surrounding the monitor. A projection provided on the diaphragm transmits movement thereof to a distortable substrate located within the chamber. A first SAW device is mounted on the distortable substrate, and at least a second and third SAW device are mounted within the chamber. The second SAW device carried on a reference substrate section has its direction of propagation inclined at an angle to the direction of propagation of at least one of the first and third SAW devices. This way movement of the diaphragm induced by a change in pressure in the zone surrounding the monitor results in distortion of the distortable substrate, which is measurable by the SAW device mounted thereon, without distorting said reference substrate section.

Abstract: A pressure monitoring device includes a rigid base (2) which has secured thereto a lid (5) to define a hermetically sealed chamber (6). The lid (5) is of flexible metal material and the major surface (5A) of the lid forms a diaphragm which will deflect in response to changes in the pressure surrounding the device. A substrate (7) upon which a plurality of SAW devices are laid down is supported on a rigid frame (3A) of the base so that the central region thereof is unsupported between edges (11, 12). A dimple (10) is formed in the lid (5) and presses on a central region of the substrate (7). Changes in pressure will accordingly cause distortion of the central region of the substrate. The end regions (8, 9) of the substrate (7) carry further SAW devices so that, by analyzing the changes in characteristics of all the SAW devices a temperature compensated indication of pressure change, together with an indication of absolute temperature, may be provided by interrogating the SAW devices.

Abstract: A pressure monitoring device comprises a rigid base (2) which has secured thereto a lid (5) to define a hermetically sealed chamber (6). The lid (5) is of flexible metal material and the major surface (5A) of the lid forms a diaphragm which wil deflect in response to changes in the pressure surrounding the monitor. A substrate (7) upon which a plurality of SAW devices are laid down is supported on a rigid frame (3A) of the base so that the central region thereof is unsupported between edges (11, 12). A dimple (10) is formed in the lid (5) and presses on a central region of the substrate (7). Changes in pressure will accordingly cause distortion of the central region of the substrate. The end regions (8, 9) of the substrate (7) carry further SAW devices so that, by analysing the changes in characteristics of all the SAW devices a temperature compensated indication of pressure change, together with an indication of absolute temperature, may be provided by interrogating the SAW devices.