The Triple Points of Krypton, Argon, Nitrogen and Neon

Abstract
The triple points of krypton, argon, nitrogen and neon have been realized with reproducibilities of ±0.2 mK, ±0.1 mK, ±0.1 mK, and ±0.2 mK respectively. The results suggest that the triple points of argon and nitrogen make excellent reference temperatures while those of krypton and neon appear to be less suitable, possibly due to problems associated with isotope composition.