New class of airflow rates control devices has been developed in MSMU Electro-engineering dpt. Acoustic method of flow rates measurement is the most perspective and free of inherent to traditional methods defects. The main characteristics of the acoustical anemometer designed are: wide range (0.1-20.0 m/s); high precision (measuring error 0.02+0.02V m/c); lag-free instrument (time of one measurement 0.01 s); possibility of interfacing with the computer; averaging during any time interval; reliability (absence of frail and moving parts). These features make acoustical anemometer an optimum for airflow velocities control, both in manual, and in the autonomous mode.

A phase difference of two acoustical signals transmitted along and against the flow is being measured. Acoustic signals are being radiated and received by piezoelectric transducers mounted in the walls of anemometric channel. A phase difference is directly proportional to average velocity of airflow through the wave duct. Theoretical and experimental researches have provided a basis of the method, construction parameters optimization, elimination of some inaccuracies (for example, caused by environment parameters changing).

Anemometers operating in mines need the regular check, and checking installation has been designed in MSMU. Developed instruments already successfully work in number of mines. In the opinion of authors, acoustics method is the most perspective direction in mine anemometry.

Sincerely, prof. S.Shkundin,
head of Electroengineering dept.