Fahrenheit reference points became popular following the work of Anders Celsius and these fixed points were adopted by a committee of the Royal Society led by Henry Cavendish in 1776. Under this system, the Fahrenheit scale is redefined slightly so that the freezing point of water is exactly 32 °F, and the boiling point is exactly 212 °F or 180 degrees higher. It is for this reason that normal human body temperature is approximately 98° (oral temperature) on the revised scale (whereas it was 90° on Fahrenheit's multiplication of Rømer, and 96° on his original scale). The Rankine temperature scale was
Carburetor heat the throttle valve, and other internal surfaces of the carburetor. The venturi effect can drop the ambient air temperature by 70 absolute degrees Fahrenheit (F), or 38.89 absolute degrees Celsius (C). In other words, air at an outside temperature of 100 degree F, can drop to 30 degrees F in the carburetor. Carburetor icing most often occurs when the outside air temperature is below 70 degrees F (21 degrees C) and the relative humidity is above 80 percent. Carburetor heat uses hot air drawn from the heat exchanger or "heat stove" (a metal plate around the exhaust manifold) to raise