METHOD AND DEVICE FOR NON-INVASIVE MEASUREMENT OF THE VELOCITY OF A GAS OR LIQUID

摘要

The invention relates to a method for non-invasive measurement of the velocity of a gas or a liquid in a test site, comprising the following steps: I) energizing the atoms and/or molecules present in the gas or liquid to an excited atom or molecule state using a first focused pulsed light beam of a light source in the test site; j) after a time interval DELTA t has elapsed, that is at least as long as the time required for the excited atoms and/or molecules to return to a metastable state by means of relaxation, the atoms and/or molecules in metastable state are selectively energized to an excited atom or molecule state using a second pulsed light beam of the light source irradiating the test site and the assumed momentary location of the spatial area containing the atoms and/or molecules and having a lower intensity in relation to the first light beam, so that a characteristic luminescence is generated; k) detecting the characteristic luminescence of the selectively excited atoms and/or molecules and determining the coordinates of the test site and the emergence of luminescence (luminescent cloud) in an image field and l) calculating the speed v of the gas or liquid on the basis of the distance s between the test site and the central point of the luminescence cloud and the time interval DELTA t as follows: v = s/ DELTA t.