Scott Air-Pak SCBA the freezing point of water at 32 degrees Fahrenheit (0 degrees Celsius) and compare it to 96 °F (35.6 °C; normal human body temperature is 37 °C). While 96 is arithmetically three times 32, the difference in temperature from a scientific point of view is not threefold. Instead of comparing 32 to 96, temperatures of 273.15 K and 308.71 K should be compared. The actual scientifically valid change in temperature from 32 to 96 °F is by a factor of 1.13 (308.71/273.15), not 3. If an air cylinder is pressurized to 4,500 psi at 96 °F and later the temperature
Autoignition temperature Autoignition temperature The autoignition temperature or kindling point of a substance is the lowest temperature at which it spontaneously ignites in normal atmosphere without an external source of ignition, such as a flame or spark. This temperature is required to supply the activation energy needed for combustion. The temperature at which a chemical ignites decreases as the pressure or oxygen concentration increases. It is usually applied to a combustible fuel mixture. Autoignition temperatures of liquid chemicals are typically measured using a flask placed in a temperature-controlled oven in accordance with the procedure described in ASTM E659. When measured for plastics,