The condition of a shoe roll is monitored by a device which continuously
analyzes the lubricant used in a lubrication system (14) integrated with
the shoe roll. The analysis determines the amount of contaminant
particles which have entered the lubricant. Particles (19) originating
from the belt (13) of a belt roll belonging to the shoe roll (10) are
determined in the lubricant. The condition of the belt (13) of a belt
roll belonging to the shoe roll (10), and especially the condition of the
inner side of the belt (13), can be determined on the basis of the amount
of the particles (19).