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Guarded-Hot-Plate Apparatus at the National Institute of Standards and Technology


NIST Virtual Museum - Guarded-Hot-Plate Apparatus at NIST

R.R. Zarr, Energy and Environment Division, Gaithersburg, Maryland

Hot-Plate Apparatus

The history of testing heat insulators at the National Institute of Standards and Technology, formerly the National Bureau of Standards, is nearly as long as the history of the institute itself.  The institute’s participation in building research provided an important role in the development of test methods for measuring the heat transmission of insulating and building materials.  The history of building activity was originally described in 1970 in the publication, Building Research at the National Bureau of Standards, prepared by Paul Reece Achenbach with input on the early history of the guarded-hot-plate apparatus (pp. 11-14) from Frank Joseph Powell.  An updated history, covering 1970 to 2000, was prepared by Richard N. Wright in the publication Building and Fire Research at NBS/NIST 1975-2000 (pp. 127-129).

The principal measurement technique presented in this history is the development and subsequent standardization of the guarded-hot-plate method.  Since 1912, 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 modern history at NIST essentially began in 1964 when Henry Emmons Robinson presented his innovative ideas on line heat-sources for guarded hot plates, 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). In 2001, Robert R. Zarr contributed A History of Testing Heat Insulators at NIST for NIST Special Publication 958 commemorating the 100th Anniversary of the founding of the National Institute of Standards and Technology. This history was expounded at an ASHRAE Symposium, “NIST Centennial – Celebrating 100 Years of NIST-ASHRAE Relationship,” in Cincinnati, Ohio.


History of NIST Guarded-Hot-Plate Apparatus

1949 Letter from H.C. Dickinson on the Development of the Guard Hot Plate at NBS - coming soon!

2001 ASHRAE Symposium Presentation (updated 2020) - coming soon!

Photograph Gallery of NIST Guarded-Hot-Plate Apparatus

Biographies of NBS Thermal Conductivity Researchers

History of Other NIST Thermal Conductivity Equipment


Created July 26, 2011, Updated September 3, 2020