View source for DBrn

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The symbol '''dBrn''' or '''dB(rn)''' is an abbreviation for '''[[decibels]] above [[reference noise]]'''.
Weighted [[noise power]] in dB is referred to 1.0 [[picowatt]]. Thus, 0 dBrn = -90 [[dBm]]. Use of 144 [[Line (electrical engineering)|line]], 144-receiver, or [[Psophometric weighting|C-message weighting]], or [[flat weighting]], can be indicated in [[Bracket#Parentheses|parentheses]].
With C-message weighting, a one-[[milliwatt]], 1000 [[hertz|Hz]] tone will read +90 dBrn, but the same power as [[white noise]], randomly distributed over a 3 kHz [[band (radio)|band]] will read approximately +88.5 dBrn, because of the [[frequency]] weighting.
With 144 weightings, a one milliwatt, 1000 Hz white noise tone will also read +90 dBrn, but the same 3 kHz power will only read +82 dBrn, because of the different [[frequency weighting]].
Note: In telecommunications, ''dBrn adjusted'' also called '''dBa''' denotes "decibels adjusted", i.e. weighted absolute noise power. This is totally unrelated to and not a synonym for [[dB(A)]].
==References==
{{FS1037C MS188}}
{{Decibel}}
[[Category:Mechanics]]
[[Category:Units of measurement]]
[[Category:Logarithmic scales of measurement]]