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 combined pressure and temperature sensor comprising a tubular member 3 of circular cross section having a closed end and an open end, the open end, in use, connecting to a pressurized environment such that the interior of the tubular member is exposed to the pressure, a flat or preferably a symmetrical distribution of flats 1 being formed on the outer cylindrical surface of the tubular member 3, and a sensor element 2 mounted on at least one said flat 1, which sensor element 2 is sensitive to the strains in the tubular wall of the tubular member 3 resulting the pressure in the interior thereof and the temperature of said tubular member.

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 sensor has a body having a tapered locking surface, and engages in a component with a mounting surface having a complementary taper to the tapered locking surface of the body. The body is positioned on the component with the tapered locking surface aligned with the mounting surface, and an axial force is applied to the body to drive the tapered locking surface into engagement with the complementary taper of the mounting surface. The body is then fixed relative to the component by swaging outwards a skirt on the body into engagement with a lower surface of the component.

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 combined pressure and temperature sensor comprising a tubular member 3 of circular cross section having a closed end and an open end, the open end, in use, connecting to a pressurised environment such that the interior of the tubular member is exposed to the pressure, a flat or preferably a symmetrical distribution of flats 1 being formed on the outer cylindrical surface of the tubular member 3, and a sensor element 2 mounted on at least one said flat 1, which sensor element 2 is sensitive to the strains in the tubular wall of the tubular member 3 resulting the pressure in the interior thereof and the temperature of said tubular member.

Abstract: A device for measuring torsional distortion of a body comprises first and second clip portions each having a central part and two legs depending from the central part, each leg having adjacent the free end thereof a groove or projection for engaging a respective projection or groove (14) provided in the body (16) to mount the clip portion the body rotationally fastened therewith. A bridge interconnects the clip portion. The bridge is less stiff than the clip portions whereby relative rotational displacement of the clip portions caused by torsional distortion of the body will cause proportional deflection of the bridge. Means, for example a SAW device (15), are provided for measuring the deflection of the bridge to provide an indication of the torsional distortion which produces the deflection of the bridge. Also (20) for the interior all of a hollow body.

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 load cell for use in dynamic testing apparatus for mechanically testing samples includes an accelerometer mounted in the load cell on the same axis as the line of action of the mechanical force applied to the specimen under test. The resultant signal from the combination of the normal output from the load cell and the output from the accelerometer compensates for errors introduced by the mass of the moving grip used to grip the specimen in the apparatus.