Figure 8. Digitizer models for the Q4120 and NARS dataloggers (at 20 samples/ sec), compared with the NLNM convolved with a noise-free sensor with a flat velocity response and a gain of 1500 V/m/sec (NL0), a noise-free STS-1 sensor (NL1), and a noise-free STS-2 sensor (NL2). The PSDs are relative to 1 V²/Hz. The figure visualizes for which frequencies the digitizer can be used without precaution.