ČSN ISO 2041 - Vibrace, rázy a monitorování stavu – Slovník
Stáhnout normu: | ČSN ISO 2041 (Zobrazit podrobnosti) |
Datum vydání/vložení: | 2020-04-01 |
Zdroj: | https://www.iso.org/obp/ui#iso:std:iso:2041:ed-4:v1:en |
Třidící znak: | 011400 |
Obor: | Mechanika |
ICS: |
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Stav: | Platná |
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Nahlásit chybu
logarithm of the ratio of a quantity to a reference of the same kind Note 1 to entry: The levels are normally defined in terms of base 10 logarithm. Otherwise, the base of the logarithm is specified. Note 2 to entry: Examples of kinds of levels in common use are electric-power level, sound-pressure level, and voltage level. Note 3 to entry: The level of sound-pressure, voltage or other field quantity, F, is normally: F = 20 lg (F/F0) The level of electric-power or another power quantity, P, is normally: P = 10 lg (P/P0) Note 4 to entry: A difference in the levels of two like quantities q1 and q2 is described by the same formula because, by the rules of logarithms, the reference quantity is automatically divided out as follows: Note 4 to entry: In vibration terminology, the term “level” is sometimes used to denote amplitude, average value, root-mean-square value or ratios of these values. These uses are deprecated.