A system for stereoscopic and real-time monitoring of an ocean methane profile includes a waterborne communication floating body, a gravity anchor, and a monitoring mechanism disposed therebetween, wherein the monitoring mechanism includes a submarine methane leakage intensity monitoring apparatus, a plurality of methane monitoring apparatus capable of synchronously monitoring methane content and a hydrodynamic environment, and a plastic-coated steel cable connected between the waterborne communication floating body and the gravity anchor; a data acquisition cabin is connected to the plastic-coated steel cable through a first communication module; and a first floating ball assembly is connected to the plastic-coated steel cable through a fixing rope. The submarine methane leakage intensity monitoring apparatus and the plurality of methane monitoring apparatus are disposed between the gravity anchor and the waterborne communication floating body at predetermined intervals.

Techniques are described herein for displacing liquid away from a signal path of sonic signals in a signal anemometer. A sonic anemometer may include a membrane positioned between a sonic transducer and the open environment. The membrane may be formed of a hydrophobic material that repels the liquid. The membrane may also include a plurality of pores that impede the flow of liquid through the membrane but enables sonic signals to pass through the membrane. The sonic anemometer may also include a reflector that displaces liquid away from the signal path of the sonic anemometer. The reflector may include one or more pores that wick liquid away from the signal path.

A body for an acoustic resonance fluid flow speed sensor or an acoustic resonance fluid flow sensor comprising such a body, the body comprising a reflector surface with at least one section that is more hydrophilic than a surrounding section of the reflector surface to promote movement of water from a centre toward an edge of the reflector surface.

An impact sensor is mounted in a duct of a grain cleaning system above an upper sieve. The impact sensor has an upstream-facing impact-sensing surface with respect to a cleaning airstream, and is configured to transduce impact events and generate impact signals therefrom. An electronic control unit (ECU) is configured to generate control signals based upon a particle energy value that is determined from the impact signals. The control signals may serve to adjust various working units of a combine harvester including, by way of example, a cleaning fan and sieves.

A method is provided to measure a distribution of axial velocities and a flowrate in a pipe or a vessel. The method comprises selecting a single cross-section at a stable-flow segment in a pipe or a vessel, installing a plurality of acoustic wave sensors along a peripheral wall of the pipe or the vessel to form a plurality of effective sound wave paths; measuring sound wave travelling time on each sound wave path; substituting the measured sound wave travelling time data into the model formulas based on a sound path refraction principle for reconstruction calculation to obtain a distribution of axial velocity in the measured cross-section of the pipe or the vessel, u(x,y); and integrating the distribution of the axial velocity u(x,y) along the cross-section to obtain a flow rate. A system is also provided to measure an axial velocity distribution and a flow rate in a pipe.

A grain cleaning system for a combine harvester having a transmitter adapted to transmit a base signal at a known frequency and one or more spaced receivers for detecting signals of a different frequency as reflected from airborne grain and other materials within the duct of the grain cleaning system An Electronic Control Unit modulates the base signal and the reflected signals to obtain Doppler signals or frequencies from which an average particle velocity is determined. The particle velocity is used as an input parameter for the generation of control signals for the adjustment of various working units of the combine harvester including, by way of example, the fan and sieves.

A method is provided to measure a distribution of axial velocities and a flowrate in a pipe or a vessel. The method comprises selecting a single cross-section at a stable-flow segment in a pipe or a vessel, installing a plurality of acoustic wave sensors along a peripheral wall of the pipe or the vessel to form a plurality of effective sound wave paths; measuring sound wave travelling time on each sound wave path; substituting the measured sound wave travelling time data into the model formulas based on a sound path refraction principle for reconstruction calculation to obtain a distribution of axial velocity in the measured cross-section of the pipe or the vessel, u(x,y); and integrating the distribution of the axial velocity u(x,y) along the cross-section to obtain a flow rate. A system is also provided to measure an axial velocity distribution and a flow rate in a pipe.

A body for an acoustic resonance fluid flow speed sensor or an acoustic resonance fluid flow sensor comprising such a body, the body comprising a reflector surface with at least one section that is more hydrophilic than a surrounding section of the reflector surface to promote movement of water from a centre toward an edge of the reflector surface.

Techniques are described herein for displacing liquid away from a signal path of sonic signals in a signal anemometer. A sonic anemometer may include a membrane positioned between a sonic transducer and the open environment. The membrane may be formed of a hydrophobic material that repels the liquid. The membrane may also include a plurality of pores that impede the flow of liquid through the membrane but enables sonic signals to pass through the membrane. The sonic anemometer may also include a reflector that displaces liquid away from the signal path of the sonic anemometer. The reflector may include one or more pores that wick liquid away from the signal path.

Techniques are described herein for displacing liquid away from a signal path of sonic signals in a signal anemometer. A sonic anemometer may include a membrane positioned between a sonic transducer and the open environment. The membrane may be formed of a hydrophobic material that repels the liquid. The membrane may also include a plurality of pores that impede the flow of liquid through the membrane but enables sonic signals to pass through the membrane. The sonic anemometer may also include a reflector that displaces liquid away from the signal path of the sonic anemometer. The reflector may include one or more pores that wick liquid away from the signal path.