Neon measurements were carried out on the GV 5400 Noble Gas Mass Spectrometer, equipped with a modified Nier-type ion source, a Faraday detector and an axial electron multiplier with the resolving power (m/Δm) of approximately 650. The neon blanks had atmospheric composition, containing ∼5 × 107 atoms of 20Ne at room temperature and ∼3 × 108 atoms of 20Ne at 1350 °C lasting for 30 min.