A METHOD FOR NOISE REDUCTION IN DATA ACQUISITION SYSTEMS

摘要

The invention relates to a method for eliminating noise in data acquisition systems. The signal to be acquired is sampled and digitised at a rate that is several times the required sampling rate. Then the sample values are averaged to derive a single representative value that is free of the influence of high frequency random noise. To eliminate the effect of low frequency systematic noise, the number of samples to be averaged must be an integral multiple of fs/fn where fs is the sampling frequency and fn is the noise frequency. Over sampling of the input signal simplifies the anti-alias filter requirements. System calibration techniques may be employed to further reduce the effect of component non-linearities, offsets, reference errors etc. and a digital multiplier, to enhance the measurement range.