- Author
- Flynn, D. R. | Zarr, R. R. | Hahn, M. H. | Healy, W. M.
- Title
- Design Concepts for a New Guarded Hot Plate Apparatus for Use Over an Extended Temperature Range.
- Coporate
- MetSys Corp., Millwood, VA National Institute of Standards and Technology, Gaithersburg, MD
- Book or Conf
- Insulation Materials: Testing and Applications, 4th Volume. ASTM STP 1426. 2002, ASTM International, West Conshohocken, PA, Desjarlais, A. O.; Zarr, R. R., Editors, 98-115 p., 2002
- Keywords
- insulation | heat transmission | conductive heat transfer | heat transfer | thermal conductivity | thermal insulation | thermal resistance
- Identifiers
- guarded hot plate; R-value
- Abstract
- The National Institute of Standards and Technology is building a new guarded hot plate apparatus (GHP) for use at temperatures from 90 K to 900 K, with provision to conduct tests in various gases at controlled pressures from 0.013 Pa to 0.105 MPa ({approximately equal to} 1.04 atm). Important features of the design of the new NIST GHP include: enclosure of the entire apparatus in a vacuum chamber; solid metal hot plates and cold surface plates to provide highly isothermal surfaces in contact with the test specimens; an integral close-fitting edge guard to minimize the effects of edge heat losses or gains; connection guard blocks to minimize the effects of heat conduction along coolant lines, heater leads, thermometry wells, and sensor leads coming from the hot plate and the cold plates; provision of a system to provide a known clamping force between the specimens and the contacting hot and cold plate surfaces; provision of an accurate system for in-situ measurement of specimen thickness during a test and the use of three long-stem standard platinum resistance thermometers to measure the average temperature of the meter plate and the two cold plates.