Temperature measurement techniques for spray foam applications

A method is presented for instrumenting specimens in a way that is minimally thermally invasive, which leads to temperature results that can be trusted as highly accurate. The thermocouple type recommended for this application is insulated Type K 36 gauge, joined via welding. Larger wire gauges result in significantly underestimated temperatures, by as much as 30 °C. In combination with thermocouple types with higher thermal conductivity of wires, this underestimation can reach as much as 60 °C. The potential inaccuracies are particularly pronounced due to the low thermal mass and low thermal conductivity of spray foam insulation.