Radiance Temperatures (in the Wavelength Range 527 to 1500 nm) of Palladium and Platinum at Their Melting Points by a Pulse-Heating Technique

The radiance temperatures (at seven wavelengths in the range 527 to 1500 nm) of palladium and platinum at their respective melting points were measured by a pulse-heating technique. The method, based on rapid resistive self-heating of a specimen from room temperature to its melting point in less than 1 s, used two high-speed pyrometers to measure specimen radiance temperatures every 0.5 ms during the heating and melting period. Melting was manifested by a plateau in the radiance temperature-versus-time function for each wavelength. The melting-point radiance temperatures for a given specimen were determined by averaging the measured temperatures along the plateau at each wavelength. The melting-point radiance temperatures for each metal as determined by averaging the results for several specimens at each wavelength are as follows. Palladium Platinum 1723 K at 529 nm 1696 Rat 626 nm 1687 Kat 657 nm 1669 Kat 720 nm 1643 Kat 811 nm 1614 K at 908 nm 1444 Kat 1500nm 1904 Kat 527 nm 1871 K at 624 nm 1859 Kat 657 nm 1838 Kat 717 nm 1806 Kat 810 nm 1773 Kat 907 nm 1577 Kat ISOOnm Based on uncertainties arising from pyrometry and specimen conditions, the expanded uncertainty (two-standard deviation level) is about +7 K for the