Abstract: An acoustic wave flow sensor is disclosed, which includes a sensor substrate and an acoustic wave diaphragm etched upon the sensor substrate, wherein mechanical stress or strain is concentrated in the acoustic wave diaphragm. One or more interdigital transducers can be configured upon the acoustic wave diaphragm, wherein the sensor substrate, the acoustic wave diaphragm and the interdigital transducer(s) form an acoustic wave flow sensor, such that when the interdigital transducer and the acoustic wave diaphragm are exposed to a fluid in flow, the fluid in flow causes the acoustic wave diaphragm to experience a change in the mechanical stress or strain resulting in a detectable frequency and/or phase change in order to provide an indication of fluid flow.

Abstract: A lubricity sensor includes a flexural plate wave device and a face shear mode bulk acoustic wave device, which is associated with and located proximate to the flexural plate wave device. The face shear mode bulk acoustic wave device and the flexural plate wave device form a lubricity sensor wherein acoustic wave data produced by the flexural plate device together with the face shear mode bulk acoustic wave device when the lubricity sensor is exposed to a liquid relates directly to a lubricity of the liquid thereby providing lubricity measurement data associated with the liquid. The acoustic wave data can comprises the oscillation gain compensation, the frequency, amplitude and/or phase velocity associated with the flexural plate device and the shear mode bulk acoustic wave device such that the oscillation gain compensation, the frequency, amplitude and/or phase velocity provide an indication of the lubricity of the liquid.

Abstract: A method and system for measuring liquid conductivity utilizing an acoustic wave sensor. In general, an acoustic wave device can be provided with one or more interdigital transducers, including at least a first interdigital transducer and at least a second interdigital transducer having a cavity formed therebetween, wherein liquid comes into contact with the cavity. For example, a liquid, such as oil, may flow through the cavity. A measurement of the resistance and/or frequency of the acoustic wave device next to the cavity can be performed in order to obtain data indicative of the conductivity of the liquid.

Abstract: A method and system for detecting oil quality. The quality of engine oil can be determined utilizing an acoustic wave sensor to obtain viscosity and corrosivity data associated with the engine oil. The acoustic wave sensor is coated with a material that selectively reacts to at least one type of an acid in order to provide data indicative of the presence of the acids in the engine oil. The etch rate or the corrosivity of the engine oil can be determined based on the frequency data obtained as a result of the frequency measurement utilizing the acoustic wave sensor. The viscosity of the engine oil can additionally be obtained based on a measurement of phase and amplitude obtained from the data utilizing the acoustic wave sensor. The etch rate and the viscosity measurement provide data indicative of the quality of the engine oil.

Abstract: An acoustic wave flow sensor is disclosed, which includes a sensor substrate and an acoustic wave diaphragm etched upon the sensor substrate, wherein mechanical stress or strain is concentrated in the acoustic wave diaphragm. One or more interdigital transducers can be configured upon the acoustic wave diaphragm, wherein the sensor substrate, the acoustic wave diaphragm and the interdigital transducer(s) form an acoustic wave flow sensor, such that when the interdigital transducer and the acoustic wave diaphragm are exposed to a fluid in flow, the fluid in flow causes the acoustic wave diaphragm to experience a change in the mechanical stress or strain resulting in a detectable frequency and/or phase change in order to provide an indication of fluid flow.

Abstract: A sensor system for detecting the presence of at least one specific component in a fluid medium such as an exhaust gas. A sensor is mounted in a sensor body for detecting the presence of at least one specific component and providing a representative signal that is transmitted to a remote receiver for processing. A power source such as a thermopile provides power for the sensor and the transmitter. Preferred are sensors that detect a plurality of different components in the gas and provide a distinct signal for each component. A preferred transmitter is designed to transmit at a low duty cycle so as to conserve power. A preferred sensor is electronic, has the capability for self-diagnostics and self-calibration, and causes a change in current when exposed to the component, such as a functionalized field effect transistor.

Abstract: A wireless oil filter sensing system includes an oil filter and a sensing mechanism that is connectable to the oil filter. The sensing mechanism includes one or more acoustic wave sensing elements and at least one antenna that communicate with the acoustic wave sensing element(s). An external interrogation system could excite the acoustic wave sensing element(s) wireless and passively. When the acoustic wave sensing elements are in contact with oil contained in the oil filter, the acoustic wave sensing elements detect acoustic waves associated with the oil in response to an excitation of the acoustic wave sensing elements, thereby generating data indicative of the quality of the oil for wireless transmission through the antenna(s).

Abstract: A multiple-mode acoustic wave sensor apparatus includes an acoustic wave device comprising a piezoelectric substrate and at least one electrode on the substrate. When such sensor is used in a wireless configuration, a plurality of antennas can be configured on the substrate in association with the acoustic wave device, wherein each antenna among the plurality of antennas is responsive to varying interrogation signals transmitted wirelessly to the plurality of antennas in order to excite multiple frequency modes via at least one interdigital transducer on the substrate and thereby passively detect multiple and varying parameters of a sensed material utilizing the acoustic wave device.

Abstract: A sensor system for detecting the presence of at least one specific component in a fluid medium such as an exhaust gas. A sensor is mounted in a sensor body for detecting the presence of at least one specific component and providing a representative signal that is transmitted to a remote receiver for processing. A power source such as a thermopile provides power for the sensor and the transmitter. Preferred are sensors that detect a plurality of different components in the gas and provide a distinct signal for each component. A preferred transmitter is designed to transmit at a low duty cycle so as to conserve power. A preferred sensor is electronic, has the capability for self-diagnostics and self-calibration, and causes a change in current when exposed to the component, such as a functionalized field effect transistor.

Abstract: A bracket 14 for mounting a lead frame 12 having pressure responsive electrical switches 20 is provided with a pair of bores 88 through the bracket at each switch station in alignment with recessed portions 78 and 86 in the bottom surface of the switch housing. A layer 92 of filter material is disposed between the bores and the recessed portions so that fluid flowing through the bores into the recessed portions will be forced to flow through the filter material to exclude particles of contamination larger than a selected size.

Abstract: A normally open pressure responsive switch having upper and lower housings with a snap acting member and an electrically conductive member sandwiched therebetween. The housings each include a body with a hollow center portion and the lower housing has a contact in the center portion extending externally of the member. The snap acting member is in constant engagement with the sandwiched conductive member and normally out of engagement with the contact. When pressure is applied which is sufficient to cause the snap acting member to snap connection is made with the electrically conductive member in the lower assembly. An elastomeric sealing member is mounted in the upper housing and has a neck portion received in the hollow center portion, an integrally attached flange biased against the electrically conductive member and lower housing and an integrally attached lobe extending above the upper housing to seal off the hollow center portion when the switch is mounted at a switch receiving seat.