Before revision: Deuterium (2H / 1H) – , about 1 in 6420 hydrogen atoms Tritium (3H / 1H) – = , measured on 16 September 1976, about 1 in 5.401017 hydrogen atoms Oxygen-18 (18O / 16O) – , about 1 in 499 oxygen atoms Oxygen-17 (17O / 16O) – , about 1 in 2640 oxygen atoms SLAP Based on the results of , the IAEA defined the delta scale with SLAP at −55.5‰ for 18O and −428‰ for 2H.
After revision: Deuterium (2H / 1H) – , about 1 in 6420 hydrogen atoms Tritium (3H / 1H) – = , measured on 16 September 1976, about 1 in 5.401016 hydrogen atoms Oxygen-18 (18O / 16O) – , about 1 in 499 oxygen atoms Oxygen-17 (17O / 16O) – , about 1 in 2640 oxygen atoms SLAP Based on the results of , the IAEA defined the delta scale with SLAP at −55.5‰ for 18O and −428‰ for 2H.