| 摘要 |
A method for operating a magnetic resonance spectrometer with a digital filter whose input is fed with an NMR signal of a time length T<SUB>A</SUB>, and whose output signal consists of a rising oscillation B<SUB>1 </SUB>of a length T<SUB>B</SUB>, a signal portion [F]' which consists of a filtered FID or echo signal of the length T<SUB>A </SUB>and a decaying oscillation B<SUB>2 </SUB>of a length T<SUB>B</SUB>, wherein this output signal is initially modified using a calculation process RV, and is subsequently transformed by Fourier transformation to a desired NMR spectrum, is characterized in that, during the calculation process RV, only the signal portion [F]' is initially selected, at least N copies of the rising oscillation B<SUB>1 </SUB>are subsequently generated in positive time shifts T<SUB>A </SUB>with respect to each other and are positioned on the signal portion [F'] in time such that the end of the first rising oscillation is positioned at the end of the signal portion, at least N copies of the decaying oscillation B<SUB>2 </SUB>are generated in negative shifts T<SUB>A </SUB>and are positioned on the signal portion [F'] in time such that the start of the first decaying oscillation is positioned at the start of the signal portion [F'], and all N copies of the rising oscillation B<SUB>1 </SUB>defined in this manner and N copies of the decaying oscillation B<SUB>2 </SUB>defined in this manner are added to the signal portion [F'], and only the range T<SUB>A </SUB>thereof which contains the signal portion [F'] is selected as resulting signal F'' of the calculation process RV, wherein the number N is to be calculated using the formula N=T<SUB>B</SUB>/T<SUB>A </SUB>and rounded to the next higher integer number. This exactly compensates for the influence of the group delay time of digital, linear-phased filters in a mathematically exact manner.
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