The measurement quoted in dB describes the ratio (10 log power difference, 20 log voltage difference, etc.) between the quantity of two levels, the level being measured and a reference.
Alt Codes for Bracketing ; Alt Code Symbol Description Alt 40 ( Open Bracket Alt 41 ) Close Bracked Alt Codes for Degree of Accuracy ; Alt Code Symbol Description Alt 241 Â± Plus or Minus Alt Codes for Fractions ; Alt Code Symbol Description Alt 47 / Fraction seperator
The standardized keyboard symbol for the Alt key (which may be used when the usual Latin lettering âAltâ is not preferred for labelling the key) is given in ISO/IEC 9995-7 as symbol 25, and in ISO 7000 âGraphical symbols for use on equipmentâ as symbol ISO-7000-2105.