Daniel R. Flynn, James H. Yen, James J. Filliben, Robert R. Zarr, E M. Hohlfeld
In the late 1950s, Corning Glass Works measured the heat capacity, thermal diffusivity, and thermal expansion of Pyroceram Code 9606. In the early 1960s the National Bureau of Standards (NBS) measured the thermal diffusivity and the thermal conductivity of that material and the U.S. Naval Radiological Defense Laboratory measured its thermal diffusivity. In 1963, NBS purchased seven large disks of Pyroceram Code 9606 from Corning Glass Works. Other activities prevented NBS from making much additional progress, during the 1960s, towards characterization of this material. In the 1960s and 1970s, the Thermophysical Properties Research Center at Purdue University fit smooth curves to the thermophysical property data that were available and, based on these recommended values, Pyroceram Code 9606 has served as a de facto reference material. Early in the 1980s, ASTM Committee C-14 on Glass and Glass Products asked NBS to establish PC9606 as an official thermal property reference material. With support from ASTM C-14 and the National Institute of Standards and Technology (NIST, formally NBS) Standard Reference Material Program, samples of the material were made available to a number of laboratories around the world for interlaboratory comparisons of thermal measurements. Based on the data from this comparison, along with selected older data, new recommended values have been derived for the thermal conductivity, thermal diffusivity, and specific heat of Pyroceram Code 9606. The derivation of these recommended values, and their estimated uncertainties, is discussed in some detail. Samples of Pyroceram Code 9606, will shortly be available as Reference Materials from the NIST Standard Reference Materials Program. Cylinders of 25.4 and 50.8 mm diameter will be available, e.g., for use with comparative cut-bar apparatus for measurement of thermal conductivity, and 12.7 mm diameter disks will be available for, e.g., laser pulse thermal diffusivity measurements.