noise level
The noise level refers to a reference level. Usually, noise is expressed as a relative value in decibels ( dB) and in absolute level in microwatts (µW), nanowatts (nW) or even picowatts (pW). An appended suffix identifies the specific reference used to measure the noise level. Therefore, noise levels are specified, for example, in dB(A), dBA0, dBm, dBM(psoph), dBm0.