Abstract

The current definition of the temperature unit kelvin is based on the triple point of water. The relative accuracy of about 2.10⁻⁷ of this definition is basically limited by the "purity" of the water in the triple point cell. In order to meet future demands for temperature measurements, it is desireable to redefine the kelvin by fixing the value of the Boltzmann constant [1]. The current value for the Boltzmann constant (k_B) has a relative uncertainty of 1.710⁻⁶, and this must be improved before redefining the temperature unit.

© 2009 IEEE