Calories (15 °C, NBS 1939) to Btu (3.9°C) conversion formula
Btu (3.9°C) = Calories (15 °C, NBS 1939) / 253.15814789
Calories (15 °C, NBS 1939) to Btu (3.9°C) calculation
Btu (3.9°C) = Calories (15 °C, NBS 1939) / 253.15814789
Btu (3.9°C) = 1 / 253.1583464909
Btu (3.9°C) = 0.00395
Calories (15 °C, NBS 1939)
The 15 °C NBS 1939 calorie is the amount of energy required to raise the temperature of one gram of water by one degree Celsius, from 14.5 °C to 15.5 °C, at standard atmospheric pressure. This specific definition was established by the National Bureau of Standards (NBS) in 1939.
Btu (3.9°C)
The Btu (3.9°C) is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit at the temperature where water reaches its maximum density which occurs at approximately 3.9°C (39°F).
