Hi,

I´m new to these forums, so I hope my question is not off-topic.

I´m trying to calculate the number of Thermal Shock + PTC cycles that are required to validate an electronic system according to GMW3172.

Apparently, the method is different in the revision of year 2004 (feb'04, I think) and in the one from dec'05.

In the latest version, there is an acceleration factor taking into account the ramp rate (ºC/min) in the Thermal Shock, based in the observations of Larry Edson.

The problem is that example on calculations in the appendix F seems to be wrong, but I don´t know if it is an error of calculation or an error in the formula.

Does anyone have experience in this subject?

Thanks
(I hope the question is not too specific...)

Can you attach the spec here for our review?

Thanks you for your interest but I believe that wouldn´t be legal.