Greetings,
Before an analog input signal is digitized by an analog-to-digital converter (ADC) in a DAQ device, an instrumentation amplifier applies a gain to the signal. An ADC has a set input range. In most situations, the input range is +/-5V or +/-10V. To maximize the number of digital divisions the ADC uses to represent the signal, the appropriate gain should be applied to use the full input range of the ADC. This leads to the idea of code width. Code width is the smallest change in a signal that a system can detect. It is calculated using the following formula:
code width = voltage range / (gain x 2^resolution in bits)
Having more gain settings available provides you with the ability to amplify a wider variety of input signal levels to
improve code width. You can determine if a DAQ device has sufficient gain settings for your applications based on the levels of your analog input signals and your desired code widths.
Good luck.
Spencer S.
