Power Sensor 10MHz-18GHz The 8484A High Sensitivity Power Sensor measures power from 0.1nW to 10 µW over a frequency range of 10 MHz to 18 GHz. Noise and drift have been reduced to less than 5% of full scale on the 300 pW range (only 15 pW) when it is used with the 435B power meter. Noise and drift are even less with the 436A, 437B and 438A power meters. 50 ohms nominal.