An Intercomparison of the High Temperature Scale

Abstract

List of laboratories taking part in intercomparison.---This paper gives results on an intercomparison of the high temperature scales in use at the Physikalisch-Technischen Reichsanstalt in Berlin, the Laboratoire Central in Paris, the Laboratory of the Philips Glowlampworks in Eindhoven, and the Laboratory of the Osram Lamp Company at Berlin with that in use in the Laboratory at Nela Park. For purpose in comparison the results of a previous intercomparison with the Bureau of Standards, the National Physical Laboratory at London, the General Electric Research Laboratory at Schenectady, and the Physical Laboratory at the University of Wisconsin are included.Method of comparison.---Several tungsten lamps that had been carefully aged and calibrated were sent to each of the foregoing laboratories and the temperatures of the lamps were measured for specified currents with a disappearing filament optical pyrometer using red glass as the monochromatic screen. The reductions necessary to make the readings comparable because a nonblack body was used are pointed out. Results of the first intercomparison are given in Table II and the final intercomparison given in Table III. Very good agreement was found in this intercomparison, the maximum difference being only a few degrees for any point of the entire range from about 1400 to 2700\ifmmode^\circ\else\textdegree\fi{}K.