The ability of the RSD to scan linearly over its temperature range is important. In design studies that led to the proof of concept emphasis was placed not just on a linear ramp, but the ability to heat rapidly to a high temperature to allow rapid screening tests and the ability to ramp slowly to allow careful tests with high quality data. The ability to accurately hold an isothermal ‘soak’ temperature was a priority. In addition emphasis was placed upon rapid transition from start to ramp and from ramp to soak. The ability to change ramp rates rapidly was necessary. From these considerations the re-circulating air bath principle was developed and as the data contained here shows the heat method developed in the RSD has allowed the operation of the RSD to meet targets and thus give the quality of data expected from all users. In addition and not discussed in this short Applications Note other design aspects were equally important, for example pressure measurement and safety.