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:
“A certain secret jealousy of the British Minister is always lurking in the breast of every American Senator, if he is truly democratic; for democracy, rightly understood, is the government of the people, by the people, for the benefit of Senators, and there is always a danger that the British Minister may not understand this political principle as he should.”
—Henry Brooks Adams (1838–1918)
“Circumstances ... give in reality to every political principle its distinguishing colour and discriminating effect. The circumstances are what render every civil and political scheme beneficial or noxious to mankind.”
—Edmund Burke (1729–1797)
“You may call a jay a bird. Well, so he is, in a measure—because he’s got feathers on him, and don’t belong to no church, perhaps; but otherwise he is just as much a human as you be. And I’ll tell you for why. A jay’s gifts and instincts, and feelings, and interests, cover the whole ground. A jay hasn’t got any more principle than a Congressman.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)