Analog data is stored by modern acquisition systems in digital form. Therefore, analog information must first be transformed to its digital equivalent using an analog-to-digital converter (ADC). In this type of system, the sample rate MUST exceed the highest frequency contained in the “detectable” input signal. This is not an option; it’s the law! In fact, the Nyquist criterion (part of the law) demands that we sample at greater than twice the highest frequency applied to the ADC. This is required to avoid aliasing, which may result in severe errors. Read more.