In a measurement method in the manufacture of paper or paperboard, different
forces
prevailing in a nip between a roll and a counter roll of an apparatus conveying
a paper or paperboard web are measured. In the method there are several measurement
points implemented with one or more film sensors (3) placed in the roll
(1) in the transverse direction of the paper or paperboard web. The measurement
information obtained from the measurement points by means of the sensor or sensors
(3) is utilized to determine the pressure distribution of the nip. The film
sensor (3) is a piezo- and pyroluminescent sensor from which the measurement
information can be received optically at least in the initial stage, or a sensor
comprising an electromechanical film (EMFi). The sensors (3) placed in the
calender roll (1) can be utilized to measure the pressure distribution of
the calender nip (N).
