Measurement of vapor pressure of neon from 25 K to 44 K

Abstract

Neon is an essential component in cryogenic fluid mixtures for efficient and scalable refrigeration cycles operated below 77K. Unfortunately, most available vapor pressure data of neon is unreliable due to outdated temperature scales or unacceptable uncertainties. This study reports vapor pressure data of neon and its critical temperature and pressure using the cryogenic phase equilibria test stand CryoPHAEQTS. Temperatures are measured with uncertainties ranging from 13mK to 19mK. Pressure uncertainties lay between 1mbar and 10mbar. The vapor pressure data is compared to literature values and the current reference equation of state, yielding good agreement close to the triple point and in the near-critical domain. The performance improvement of the reference EoS over the previous one is confirmed with an average relative deviation of 0.3% to our data.