Digital filter selection process

Signal filtering — A process used to eliminate unwanted frequencies, generated by electronic devices during the detection procedure, from a measured signal. Different analog filters and digital filters have been developed to increase the SNR. There are three common kinds of filters that can be implemented by hardware media and used to select the band of measured frequencies ... 

Figure 6.25. The HMBC long-range correlation spectrum of 6.2 recorded with A = 60 ms and with gradient selection. The sequence used the low-pass J-filter (Section 6.4.1) to attenuate breakthrough from one-bond correlations (which appear with Jch doublet structure along fj (arrowed)). IK ta data points were collected for 256 ti increments of 8 transients each and the data processed with unshifted sine-bells in both dimensions, followed by magnitude calculation. After zero-filling once in ti the digital resolution was 4 and 80 Hz/pt in f2 and fi respectively.

Since DCSs are based on digital controller calculations, a wide variety of special control options are available in self-contained modular form. These can be easily selected by click and drag action on some DCSs. In this manner, complex control configurations can be conveniently assembled, interfaced, and implemented. In addition, a variety of signal-conditioning techniques can be applied to process measurements, including filtering and validity checks. 

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