10.14.4 When it is required to report the temperature
reading at a prescribed percent evaporated or recovered for a
sample that has a rapidly changing slope of the distillation
curve in the region of the prescribed percent evaporated or
recovered reading, record temperature readings at every 1 %
recovered. The slope is considered rapidly changing if the
change in slope ( C) of the data points described in 10.14.2 in
that particular area is greater than 0.6 (change of slope (F ) is
greater than 1.0) as calculated by Eq 1 (Eq 2).