Which of these accelerometers' sensitivities would best measure very low amplitude vibration?

The best choice for measuring very low amplitude vibration is the option with the highest sensitivity, which is 500 mV/g. Sensitivity in accelerometers refers to the output voltage generated per unit of acceleration, typically measured in millivolts per gravitational unit (mV/g). A higher sensitivity indicates that the accelerometer can produce a larger output voltage for a given small vibration, making it easier to detect subtle changes in acceleration.

In the context of measuring low amplitude vibrations, having an accelerometer with 500 mV/g sensitivity means that it can effectively capture smaller vibrations with greater precision. When vibrations are minimal, using a sensor with lower sensitivity would result in smaller output signals, which may be difficult to distinguish from noise, leading to potential inaccuracies in measurements. Therefore, the option with 500 mV/g will provide a much clearer and more reliable signal for analysis in applications where low amplitude vibrations are of interest.