The present invention is related to a method for verifying the operational condition of a rectangular baler used for gathering crop material and forming it into a rectangular bale, the baler comprising a baling chamber (18) equipped with a reciprocating plunger (24) driven by a mechanism comprising a crank shaft (26) and one or more connecting rods (25), for forming crop material into a rectangular shaped bale, the plunger moving between a fully retracted position and a fully extended position, the baler being further equipped with a load sensor (40) suitable for determining the reaction force on the plunger as said plunger is compressing crops in the baling chamber (18), the method comprising the steps (performed while running the baler at a given speed of the crank shaft)of measuring the reaction force on the plunger (24) or a parameter related to said reaction force, when the plunger is in a position in which it is not exerting a compressive force on the crop material in the baling chamber, comparing the measured reaction force or the parameter to a predefined reference value, and deriving from that comparison an assessment of the balers condition. The invention is equally related to a baler equipped with means for performing the method of the invention.
