where fl is the time between tests at the higher temperature, f2 at the lower temperature, and "delta" is the difference in degrees centigrade between the two. For a product with a Q10 of 2, tested each week at 30°C, the frequency at 20oC would be:
F2 *1*2 10/10 or f2 = 2 weeks
Each testing temperature should have at least six data points over time to make the study results statistically reliable
The results should be plotted as they are developed in order to ensure the experimental design working properly and changes can be made in the testing frequency, if necessary
Thoroughly document all of the data so that results can be pooled with the results of a whole product line. Lessons learned can mean the next project is much simpler to design and carry out.