The -hp- Model 3582A is a dual-channel spectrum analyzer covering the frequency range of 0.02 Hz to 25.6 kHz. By combining advanced digital processing techniques and a powerful micro-computer, it can provide measurement capability previously found only in complicated computer systems. The performance features of the instrument provide optimal solutions to the problems of low frequency spectrum analysis. Frequency spans from 1 Hz to 25 kHz full scale allow great flexibility in selecting the portion of the spectrum to be analyzed. The spans from 5 Hz up to 25 kHz can be positioned anywhere within the frequency range of the instrument to provide exceptionally good frequency resolution. Without resorting to external signal conditioning, the instrument can measure input from +30 dBV (31.6 volts) down to -120 dBV (1 microvolt). Even with this high sensitivity, the input circuits are protected against overloads of up to 100 volts. For measurements where the signal of interest exists in the presence of large unwanted signals, the wide 70 dB dynamic range of the instrument is important.