What is the Ampule Test?
The Ampule Test is generally accepted as an industry standard to test relative thermal stability between heat transfer fluids. A standard ASTM-type Ampule Test is in development and the data generated by such testing has proven reliable over the course of many years. Variations between methods exist as to the composition and diameter of the ampules, the method by which the oxygen is removed from the ampule, the sample size, and the temperature run. However, with the exception of those methods which do not properly provide for oxygen removal, the relative results are reliable as long as uniform temperatures are maintained across the oven. Radco Methodology for Comparing Thermal Stability of Heat Transfer Fluid Thermal stability can be defined as the time rate of change of the chemical composition of a fluid from its initial components to its degradation products at a given temperature. To compile this information over a range of temperatures, fluid samples are capped with nitrogen to re
