Initial Measurement Results of the NIST 500 mm Guarded-Hot-Plate Apparatus Under Automated Temperature and Pressure Control

Abstract

The initial thermal conductivity measurements from a guarded-hot-plate apparatus using multiple line-heat sources are presented for specimens of high-density molded fibrous-glass board. Measurements at ambient air pressures agree to 1 % with predicted values assigned for SRM 1450c, Fibrous Glass Board, over a moderate temperature range of 280 K to 340 K. Thermal conductivity measurements at 310 K for chamber pressures from 0.004 kPa (0.03 torr) to 100.4 kPa (750 torr) are also presented. Temperature and pressure control strategies for the apparatus under these operating conditions are discussed