Ultrasonic anemometers systems for sensing air flows in rooms and ducts

A room anemometer apparatus, comprising:

• (a) a plurality of ultrasonic transceivers oriented towards each other in three-dimensional space, said transceivers configured to transmit and receive soundwaves along paths between transceivers;
• (b) a control processor operably coupled to the transceivers configured to activate each transceiver, detect transmitted soundwaves, measure differential times of flight (TOF) of the soundwaves of each transceiver and to determine wind velocity along each sound path;
• (c) an onboard compass and accelerometer/inclinometer that allows the room anemometer to continuously correct for changes that may occur in its orientation and to output a true earth-based azimuth and altitude for the wind velocity vector;
• (d) a base;
• (e) a plurality of transceiver support struts mounted vertically to the base;
• and
• (f) transceiver orienting stubs coupled to the struts, each transceiver mounted to a stub;
• (q) wherein each support stub fixes a direction of a transceiver);
• (h) wherein said room anemometer is configured to measure 3D air velocity vectors, air speed, and temperature within an open space;
• and
• (i) wherein sonic pathways are arranged along the four vertices of a tetrahedron;
• and
• (j) wherein the apparatus measures a 3-dimensional vector of wind speed and direction within the small volume of the tetrahedron.

An air movement monitoring system, comprising:

• (a) one or more anemometers, each anemometer comprising:
• (i) a plurality of ultrasonic transceivers oriented towards each other in three-dimensional space, said transceivers configured to transmit and receive soundwaves along paths between transceivers;
• and
• (ii) a control processor operably coupled to the transceivers configured to activate each transceiver and detect transmitted soundwaves;
• and
• (b) a central controller in communication with each control processor of said anemometers configured to receive detected soundwave signal data and control the anemometers, said central controller having a processor and a non-transitory memory storing instructions executable by the processor, wherein said instructions, when executed by the processor, perform one or more steps comprising:
• (i) actuating said ultrasonic transceivers individually to transmit soundwaves;
• (ii) simultaneously receiving soundwave signals along multiple signal paths;
• (iii) measuring differential times of flight (TOF) of the soundwaves;
• (iv) determining moving air velocity along each path;
• and
• (v) processing the soundwaves to measure air velocity and temperature in both homogeneous and inhomogeneous flow fields based on measuring phase angle of a few cycles within pulsed soundwave signals.