Line Heat-Source Guarded Hot Plate

Laboratory services for thermal resistance measurements (and related thermal properties) are provided for thermal insulation (and building materials) having thermal conductivities of 0.02 W·m -¹·K-¹ to 0. 15 W·m-¹·K-¹. In general, the highest accuracy is obtained for homogeneous specimens.; The preferred size for the test specimen is 1016 mm in diameter; the minimum size, 610 mm square. Customers can supply their own material for specimens, or request NIST to select specimens from an in-house inventory of fibrous-glass material. All tests are performed at an ambient atmospheric pressure of approximately 100 ± 20 kPa (site pressure at Gaithersburg, MD). Services at ambient pressures outside these limits or with other gases are not provided. A dry-air purge is available to reduce the relative humidity to less than 15 percent. Additional information on the apparatus is available in the reference, below. Laboratory capabilities are summarized below.