I suppose simplicity is key.
If I apply a constant heat to one side of the material and measure the temperature on the reverse after a set time, the better insulator would have a lower figure. Would this suffice?
I'm going to be reviewing some insulated sheets for lining walls. I want to set up an experiment to rank different types of sheet by their level of insulation.
I intend to use a digital thermometer with a probe (for example...