The SPRED spectrometer is a VUV survey instrument that has been successfully employed on a number of plasma machines. Its use of a holographic grating results in a flat focal field, enabling the best spectral resolution to be achieved over the whole extent of the detector. A double SPRED spectrometer having two fixed gratings and two independently controlled detectors has been installed on the JET machine for the observation of the divertor plasma. An additional improvement over previous SPRED designs is the extended wavelength coverage of the detectors. The experimental setup, including the spectrometer design, the VUV detectors, the alignment and control systems are described. The commissioning of the spectrometer on JET has allowed the performance of the instrument to be assessed, in particular its wavelength calibration, spectral resolution and the effect of the integral shielding to nuclear radiation-induced noise. First results include a comparison with the spectral emission from the bulk plasma of the JET tokamak, observed with a single SPRED instrument, which emphasizes that the dominant emission from the divertor originates from low ionization stages of low Z-impurities such as carbon. Evidence has been found for the localization of the line emission from within the divertor chamber and some features of the divertor VUV radiation during high performance plasmas are described. Future applications are also discussed.