For any given measurement system, you will need the right hardware. There are a few specific points that you should consider to evaluate which is the best hardware to use for data acquisition. First you have to determine the required sampling rate of the signals that you want to measure. Ideally, data acquisition devices come with different sampling rate capabilities that can range anywhere from 1 Hz on the lower side to 1 MHz on the higher side, depending on the signal measured. Follow the good rule of thumb of Nyquist Theorem that states that all signals must be sampled at 2-times the frequency of it.
Precision of the device
You must also know the precision level of the data acquisition device. If you are using the commercial analog-to-digital technology, then the sampling rate capability must be inversely proportional to the resolution or accuracy. The accuracy must be between 12 to 24 bits for most data acquisition hardware. You must also consider the type of sensors that are needed for the signals as these are essential for any data acquisition device. These help in convertingthe physical phenomenon like pressure, temperature, or vibration to electrical signals usually voltage that is usually measured by a data acquisition system.
Conditioning and environment
Sometimes signals may need conditioning as most sensors produce signals at very low amplitudes. It may also include undesirable environmental noise, commonvoltage errors due to differences in ground potentials and others. Conditioning the signals will compensate for these unwanted elements and occurrences by using filtering, signal amplification, and electrical isolation. Consider the environment in which your data acquisition system will operate. The location, ruggedness, footprint requirements, and environmental harshness, temperature, functional shock and vibrationare some other factors to consider choosing the right type of data acquisition hardware to use for your specific purpose.
