Abstract: Transducer systems with reduced acoustic noise coupling are disclosed herein. In some embodiments, a transducer system includes pressure balancing features to prevent a floating portion of the transducer system from contacting a fixed portion of the transducer system, or to reduce the degree to which the floating portion is urged into contact with the fixed portion by process pressure or atmospheric pressure. In some embodiments, a transducer system includes one or more acoustic dampening elements, interruption grooves, annular projections, or dampening washers to reduce acoustic noise coupling between various components of the transducer system or between the transducer system and a flowcell in which the transducer system is mounted.

Abstract: Transducer systems with reduced acoustic noise coupling are disclosed herein. In some embodiments, a transducer system includes pressure balancing features to prevent a floating portion of the transducer system from contacting a fixed portion of the transducer system, or to reduce the degree to which the floating portion is urged into contact with the fixed portion by process pressure or atmospheric pressure. In some embodiments, a transducer system includes one or more acoustic dampening elements, interruption grooves, annular projections, or dampening washers to reduce acoustic noise coupling between various components of the transducer system or between the transducer system and a flowcell in which the transducer system is mounted.

Abstract: An acoustic waveguide system including a waveguide, a housing with a port in one side of the housing for receiving the proximal end of the waveguide, the port opening into a channel in the housing. A first shear transducer is located in the channel of the housing and disposed on the waveguide, and a second shear transducer is located in the channel and disposed on the opposite side of the waveguide. The first and second transducers are configured to launch a torsional or an extensional wave in the waveguide depending on the orientation and polarity of the transducers.

Abstract: An acoustic waveguide system including a waveguide, a housing with a port in one side of the housing for receiving the proximal end of the waveguide, the port opening into a channel in the housing. A first shear transducer is located in the channel of the housing and disposed on the waveguide, and a second shear transducer is located in the channel and disposed on the opposite side of the waveguide. The first and second transducers are configured to launch a torsional or an extensional wave in the waveguide depending on the orientation and polarity of the transducers.

Abstract: A guided torsional wave sensor has a cross-section with a strong interaction of torsional wave energy and the surrounding fluid, such that a wave propagates in the sensor with a functional dependence on a single fluid characteristic. In one embodiment, the sensor body is optimized for fluid density. Diamond, polyhedral and curved-sided embodiments are described. In another embodiment, the sensor body responds to fluid viscosity. This embodiment is preferably hollow, and may include threaded, fractal or roughened surface features to enhance viscous coupling. Different systems include further sensors, sensors with portions of differing profile, and special mounting or activation structures.