The VUV emission of tungsten in WEST is measured by an absolutely calibrated grazing incidence spectrometer of the Schwob-Fraenkel type which can scan the lower half of the plasma. We have analysed the detected spectral lines in the range 120-140 Å and compared their behaviour with calculations and published information. We obtained an unambiguous identification of four intense and well resolved spectral lines emitted by W$^{42+}$-W$^{45+}$ close to the magnetic axis in the analysed experiments. The measured spectral line brightnesses are used to assess the Tungsten density in the emission region. In a case of a scanning line of sight, we investigate the possibility to calculate the Tungsten density profile from the angular brightness profiles. In a case of a fixed line of sight, we deduce from the measurements the core Tungsten density profile evolution during a radiative collapse.