FIELD: electric measurement technology. SUBSTANCE: power levels P0, P1 and P2 of noise signal are measured at output of noise signal power meter whose input is matched, at output of noise signal reference source with noise temperature T with its output higher or lower than ambient temperature To, and at output of amplifier under check whose input is matched, respectively. Then noise signal power level P2 is varied at output of amplifier under check until it reaches P2=P1 level at P1>P0 or P2=2P0-P1 level at P1<P0, and M value of this variation is measured. Then noise temperature Tn of amplifier under check is found from equation 
for P1>Po or from equation 
for P1<P0, where α,β is insertion loss of channel from input of amplifier under check and noise signal reference source, respectively to input of noise signal power meter, rel. units; Kamp is checked amplifier gain, rel.units. EFFECT: improved measurement accuracy. 1 dwg
