Wind speed 3 May 1999 is often quoted as the highest-recorded surface wind speed, although another figure of has also been quoted for the same tornado. Yet another number used by the Center for Severe Weather Research for that measurement is . However, speeds measured by Doppler radar are not considered official records. An anemometer is one of the tools used to measure wind speed. A device consisting of a vertical pillar and three or four concave cups, the anemometer captures the horizontal movement of air particles (wind speed). Another tool used to measure wind velocity includes a GPS combined with pitot
Lebesgue measure not have some curious properties which causes a discrepancy in the measure of another set when formula_6 is used as a "mask" to "clip" that set, hinting at the existence of sets for which the Lebesgue outer measure does not give the Lebesgue measure. (Such sets are, in fact, not Lebesgue-measurable.) The Lebesgue measure on R has the following properties: All the above may be succinctly summarized as follows: The Lebesgue measure also has the property of being "σ"-finite. A subset of R is a "null set" if, for every ε > 0, it can be covered with countably many