If the specimen continues to burn, with a flame or
glowing combustion (visible glow without flame), after removal
of the test flame, record the elapsed time (t), in seconds,
for the flame front to travel from the 25 mm reference mark to
the 100 mm reference mark and record the burned length (L),
as 75 mm. If the flame front passes the 25 mm reference mark
but does not reach the 100 mm reference mark, record the
elapsed time (t), in seconds, and the burned length (L), in
millimetres between the 25 mm reference mark and where the
flame front stopped.