Talk:Neper

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All the sources claiming that the value in nepers is \ln\frac a b are also saying that in decibels it is 20\log\frac{x_1}{x_2} which is patently incorrect, decibels are clearly defined such that it is 10 \log \frac{x_1}{x_2} - assuming the ratio between decibels and nepers are correct it is \tfrac 1 2\ln\frac{x_1}{x_2} as given in [1] [2] and [3]

http://www.its.bldrdoc.gov/fs-1037/fs-1037c.htm gives a clue as to where the 20 came from, but it needs to be made clear that the version with 20 and without 1/2 is specifically for power ratios in terms of values given in terms of voltage or current, rather than for power ratios in terms of power or ratios of any other quantity given in terms of that quantity.

It looks like 20\log\frac{x_1}{x_2} is supposed to be 10\log\frac{x_1^2}{x_2^2} where x2 is a quantity that varies as the square of the quantity whose ratio is being considered in nepers.

--Random832 (contribs) 17:54, 28 April 2008 (UTC)