One decade (symbol dec[1]) is a unit for measuring ratios on a logarithmic scale, with one decade corresponding to a ratio of 10 between two numbers.[2]
^ISO 80000-3:2006 Quantities and Units – Space and time
^"Decade, a factor, multiple, or ratio of 10", Andrew Butterfield & John Szymanski (2018) A Dictionary of Electronics and Electrical Engineering, fifth edition, Oxford University Press, ISBN9780191792717