1. The problem statement, all variables and given/known data I am required to conduct a thermal shock test where by a stainless steel object (complicated geometry) is to go from one tank of light oil at -55°C to another tank of the same light oil at +140°C, then back the -55°C tank. This is to be repeated 5000 times. In order to roughly determine how long the test shall take (primarily for costing reasons), I need to know once the test object is at -55°C and it is transferred to the hot tank at +140°C, how long it takes to reach +140°C. I assume to go from +140 to -55°c will take the same time? The transfer time between the two tanks is known and will be quoted as a maximum time. This will be added to the heat transfer time that I am looking for. Both tanks are to be constantly held at their respective temperatures. 2. Relevant equations Q=mCΔT 3. The attempt at a solution I can find values for specific heat capacity and coefficient s of heat transfer, but I am not sure how to use them in this situation. Do I use the difference of the heat capacities of the steel and the light oil? It seems correct to consider the properties of both the test object and the fluid it is submerged in. Is it as simple as using the equation above and then applying the work that can be done by the heating/cooling equipment of the relevant tanks? But as I stated earlier, the tanks are to be held at temperature. I am sure this is a fairly simple solution and I am missing something key to it! any help will be greatly appreciated.