Principle
Ultrasonic flow meters measure the difference of the transit time of ultrasonic pulses propagating in and against flow direction. This time difference is a measure for the average velocity of the fluid along the path of the ultrasonic beam. By using the absolute transit times both the averaged fluid velocity and the speed of sound can be calculated. Using the two transit times and and the distance between receiving and transmitting transducers and the inclination angle one can write the equations:
and
where is the average velocity of the fluid along the sound path and is the speed of sound.
Read more about this topic: Ultrasonic Flow Meter
Famous quotes containing the word principle:
“The world is not dialectical—it is sworn to extremes, not to equilibrium, sworn to radical antagonism, not to reconciliation or synthesis. This is also the principle of evil.”
—Jean Baudrillard (b. 1929)
“The principle of avoiding the unnecessary expenditure of energy has enabled the species to survive in a world full of stimuli; but it prevents the survival of the aristocracy.”
—Rebecca West (1892–1983)
“The first principle of a free society is an untrammeled flow of words in an open forum.”
—Adlai Stevenson (1900–1965)