Flat weighting
Encyclopedia
Flat weighting: In a noise
-measuring set, a noise weighting
based on an amplitude-frequency
characteristic that is flat over a frequency range that must be stated.
Note 1: Flat noise power
is expressed in dBrn
(f1 - f2) or in dBm
(f1 - f2). Note 2: "3 kHz flat weighting" and "15 kHz flat weighting" are based on amplitude-frequency characteristics that are flat between 30 Hz and the frequency indicated.
Noise
In common use, the word noise means any unwanted sound. In both analog and digital electronics, noise is random unwanted perturbation to a wanted signal; it is called noise as a generalisation of the acoustic noise heard when listening to a weak radio transmission with significant electrical noise...
-measuring set, a noise weighting
Noise weighting
A noise weighting is a specific amplitude-vs.-frequency characteristic that is designed to allow subjectively valid measurement of noise. It emphasises the parts of the spectrum that are most important....
based on an amplitude-frequency
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
characteristic that is flat over a frequency range that must be stated.
Note 1: Flat noise power
Noise power
In telecommunication, the term noise power has the following meanings:# The measured total noise per bandwidth unit at the input or output of a device when the signal is not present.# The power generated by a random electromagnetic process....
is expressed in dBrn
DBrn
The symbol dBrn or dB is an abbreviation for decibels above reference noise.Weighted noise power in dB is referred to 1.0 picowatt. Thus, 0 dBrn = -90 dBm...
(f1 - f2) or in dBm
DBm
dBm is an abbreviation for the power ratio in decibels of the measured power referenced to one milliwatt . It is used in radio, microwave and fiber optic networks as a convenient measure of absolute power because of its capability to express both very large and very small values in a short form...
(f1 - f2). Note 2: "3 kHz flat weighting" and "15 kHz flat weighting" are based on amplitude-frequency characteristics that are flat between 30 Hz and the frequency indicated.