Once a material series is selected, choosing a durometer within that series is important. While many factors can come into play depending on the device and isolator design, there are two questions which serve as a good starting point for durometer selection. First, what is the normal operating temperature or temperature range; and second, what is the “problem” frequency or frequencies present in the device or component. Once the designer has these numbers in hand, a comparison of material nomograms will show which material durometers exhibit the highest loss factor given for those conditions. In general, a higher loss factor is better as it will dissipate the most energy. In the example shown here, the designer sees a side by side nomogram comparison of two C-8000 series damping elastomers. Looking at the red curve of each, notice that both have similar peak loss factors greater than 1; however, those peaks occur at different points within the graph.