Question

What is meant by the term `dynamic range' in the context of a data acquisition system? How can selection of
the wrong dynamic range affect either (a) the precision of the experimental measurements, or (b) capture of
the entire signal of interest.

Answer 1

Dynamic range describes the range of the input signal levels that can be reliably measured simultaneously, in particular the ability to accurately measure small signals in the presence of the large signals. According this definition the dynamic range may be a useful parameter of any system and is the very important parameter of the measurement system.
There exist some applications (spectral analysis, nuclear magnetic resonance or tomography, communicationby power net, etc.) where the dynamic range should be as high as possible.

Limitation by spurious signals:
The spurious signals are mostly more dangerous than the noise. They have a higher amplitudethan noise and their amplitude does not depend on the used passband. Even with
accumulation we can not suppose, that they will be eliminated. Spurious signals are given by
all non linearity and their main source of them is ADC. According to their origin we can divide spurious to these groups:
a) Spurious signals given by quantization. If the input signal of an ideal ADC is noiseless, the quantization error is not noise, but a set of spurious. This spurious can be fully transferred to noise, if the input signal includes a noise with an amplitude at least 0.35 LSB rms.