The air flows in a Sigma Chamber from top to bottom. Consider a plane that is perpendicular or normal to this flow vector. Additionally, the devices must be as evenly spaced front to back and side to side on this plane so that the air flows as evenly and efficiently around each device. If you have large mass devices to test, your Sigma Systems sales engineer can help you determine how much heating or cooling capacity will be required to achieve the results you need. Buying enough capacity to do the job correctly will result in far better and more accurate testing and improve throughput.
Thermal uniformity is achieved partially through the aluminum mass of the platform.
For loading calculations, please consult with your Sigma Systems sales engineer.