Precision deuteron NMR signal measurement with the NA47 polarized target

The measurement of the deuteron polarization in the polarized target of experiment NA47 at CERN has been much improved over that of previous measurements in other experiments. This has been achieved by upgrading a proton NMR system to a level such that the deuteron thermal equilibrium polarization was measured with a statistical error of 3%. The improvements made in signal detection and measurement are described and overall system performance discussed.