These cells are used to correlate radiation thermometers to the ITS-90 scale and provide the highest accuracy
blackbody sources available. All cells contain 99.9999% pure metals and will provide a melt or freeze curve to within
±0.01°C. The primary cells used in our larger sources will provide significantly longer plateaus. The results, as seen
by radiation pyrometers, which are slightly sensitive to wall temperature, give uncertainties of better than ±0.25°C.
Easy replacement allows one apparatus to work with multiple cells.
