This work package is an essential part of the MultiFixRad project which main goal is the construction of fixed point cells of Al, Ag, Cu, Fe-C, Co-C, Pd-C, Pt-C and Re-C that cover a temperature range from 660.323 °C (Al cell) up to 2474.69 °C (Re-C cell). The cell construction will reflect their primary form of use as the calibration artefact for the calibration of measurement devices in non-contact thermometry.
The WP2 is specifically divided into three tasks that will cover the preparations for fixed point cell construction, construction of fixed-point cells themselves and the characterisation of fixed-point cells together with their optimisation of the phase transition realisation.

(i) The first tasks aim is to complete the necessary preparations for the construction of the fixed-point cells. This includes the optimization of cells geometry, purchase of carbon materials for the construction of cell crucibles and the appropriate (pure and eutectics) filling materials. All of these activities will build on the training undertaken in work package one and will augment that training with laboratory visits to the experienced NMIs, CNAM/LNE, in order for staff at the less experienced institutes to gain practical experience. Finally, this task will ensure that participants have the necessary mechanical fittings to enable reliable mounting of the fixed-point cells in the furnaces.

(ii) The second task aims to complete the construction of the fixed-point cells at their own laboratories in a way that they can be metrological characterised and used for calibration purposes. The minimal expected number of cell that should be constructed within the projects lifetime is set for 28 which are distributed over eight metrological laboratories.

(iii) The last task in the work package two is dedicated to the characterization and documentation of constructed cells performance from the view of radiation thermometry. Based on the initial result an adjustment of the realization process will be realized in order to achieve the currently best possible metrological parameters. The characteristics / parameters of interest are the phase transition duration, stability, repeatability and slope of phase transition. This characterisation is essential for the determination of the contribution of individual cells to the overall uncertainty budget. The aimed uncertainty in the practical realisation of the transition temperature of less than 0.6 °C (k=2).

The successful outcome this work package will form the basis for the next parts of the MultiFixRad project that focus on the establishment of scale implementations using the multi–fixed point scheme and on the multilateral comparison with potential linkage to the CCT-K10 key comparison.

WP leader: Peter Pavlasek (SMU, Slovakia)