R.R. Zarr, Building Environment Division, Gaithersburg, MD
For more than eighty years NIST has provided literally thousands of thermal conductivity tests on a variety of insulation materials that have been made available to the engineering and scientific professions and have been incorporated in handbook tabulations. The history of this activity has most recently been described in the publication, "Building Research at the National Bureau of Standards," prepared by P.R. Achenbach and F.J. Powell (Building Science Series 0, Government Printing Office, Washington, D.C., 1970), which includes the early history of the guarded-hot-plate apparatus at NIST. The modern history essentially began in 1964 when H.E. Robinson of NIST presented his novel ideas on line heat-sources for guarded hot plates which were later formalized in the publication, "Robinson Line-Heat-Source Guarded-Hot-Plate Apparatus," by M.H. Hahn, H.E. Robinson and D.R. Flynn ( ASTM STP 544, Philadelphia, PA, 1973).