Water-Triple-Point-Cellsvol1 The Water Triple Point is the most important fixed point, the only point common to the ITS-90 and the Thermodynamic Temperature Scale. It is an essential temperature reference standard for every temperature laboratory. The Jarrett-Isotech water triple point cell is the best standard. Not all cells are the same. Accept no inferior device. *Fifty Years of Proven Use *Uncertainty 0.000070°C *Quartz Glass and Isotopic Analysis Available