Twelve years of high temperature fixed point research: A review

A review of research into high temperature fixed points (HTFPs), since their inception at NMIJ in 1999 until 2011 is given. HTFPs discussed in this paper are those whose transition temperatures are above the freezing point of copper and based on eutectic/peritectic alloys. The paper will begin with an historical overview; including a description of the different types of modern HTFPs. The evolution of construction methods of HTFPs will be elaborated. The performance of the current generation of HTFPs will be compared to that of earlier ones. Current uses of HTFPs will be described. Finally an overview of some remaining research issues will be given including assignment of definitive thermodynamic temperatures and inclusion into the developing mise en pratique for the definition of the kelvin.