Discussion on Experiments to Separate the “Effect of Thickness” from Systematic Equipment Errors in Thermal Transmission Measurements
SourceThe radiation-related “effect of thickness” in nonhomogeneous insulations can be readily confused with equipment-related effects resulting from increases in the thickness of the measurement. The relatively unexplored effect-of-thickness phenomenon and the requirements imposed by the ASTM Tests for Steady-State Thermal Transmission Properties by Means of the Guarded Hot Plate and Heat Flow Meter (C 177–76 and C 518–76, respectively) have prompted the rapid development of equipment to measure insulations at full-use thickness.
This paper discusses the problems which arise from attempts to accurately measure insulations at full thickness, a relatively unknown area of measurement, and suggests a method for the separation of the actual effect-of-thickness phenomenon from the errors induced by the equipment.