Dynalene has the versatility to test samples by various techniques. Depending on your sample type, size or preferred method, we can use our ASTM C518 method, laser flash or transient hot wire techniques to analyze your sample. Whether insulation, cement, layered, solid, liquid or paste, Dynalene can provide you with fast and reliable results.
Sample types include:
What is R-Value and Emissivity?
R-value is a measure of thermal resistance and is commonly used in the building industry to measure insulative properties of materials (like the insulation between the walls of your home). It is the ratio of the temperature difference across the material relative to the heat flux. When we determine the R-Value we are actually measuring the thermal conductivity and performing a calculation to generate the value
For complex issues, such as the best insulation for space shuttle re-entry or something as simple as insulating your home from extreme temperatures, thermal conductivity, R-value and U-Value can help you to design a high-performance system.
Emissivity is the amount of infrared energy emitted by a specific material relative to that emitted by a blackbody at the same temperature. The emissivity of a surface depends not only on the material but also on the nature of the surface. For example, a clean and polished metal surface will have a low emissivity, whereas a roughened and oxidized metal surface will have a high emissivity A material with a low emissivity value will ‘reflect’ heat and increase the effectiveness of your insulation and decrease the energy needed to cool your home. Conversely a material with high emissivity will ‘absorb’ heat and benefit buildings located in colder climates by retaining heat and reducing the heating load.
Our ASTM C518 ‘hot box’ instrument measures the R-value by creating a steady state temperature gradient across the material. We measure the heat flow through the sample using a heat flow meter and compare this to the temperature differential to generate the R-value.
Our laser flash measurement is based on the well-known flash method. In this method, the front side of a plane-parallel sample is heated by a short light pulse. The resulting temperature rise on the rear surface is measured using an infrared detector. By analysis of the resulting temperature versus-time curve, the thermal diffusivity can be determined.
Our transient hot wire instrument applies heat to the sample in the form of a very quick pulse. The wire measures both the heat pulse and temperature of the material sample and applies a mathematical model to fit the temperature versus-time curve.