A Guide to Data Acquisition Specifications for Time and Frequency Domain Measurements

摘要

Determining the important specifications for your measurement application depends on whether you are interested in time domain or frequency domain measurements. Time domain measurements require accurate measurements of the level and shape of the waveform. Your measurement accuracy is determined by how well the voltage measurements returned by the data acquisition device reflect the input signal. The most important specification that describes this uncertainty is the absolute accuracy. Ideally, the device vendor should supply a table of absolute accuracy specifications. If your measurement application requires frequency domain measurements, you must look at a different set of specifications. Some of the important frequency domain specifications include spurious free dynamic range and signal-to-noise plus distortion ratio. When evaluating different data acquisition devices, it is critical to carefully examine the specifications provided by the manufacturer. They must supply you with enough information to reliably determine the overall uncertainty of your measurements.