Arrangement in connection with central lubrication system

An arrangement in connection with a central lubrication system, the arrangement comprising

• a lubricant vessel,
• a pump unit,
• a control unit,
• pipe systems,
• a pressure monitor unit,
• at least one feeder provided with at least one magnetizable piston that moves due to the influence of the pressure of a lubricant present in the pipe system to be lubricated, and
• a movement monitor unit for each feeder configured to monitor the operation of the central lubrication system, the lubricant being arranged to be pumped from the lubricant vessel along the pipe to the feeders and objects to be lubricated, wherein the movement monitor unit is entirely located outside a pressurized space of the corresponding at least one feeder, the pressurized space being formed by at least one wall, wherein the movement monitor unit comprises both a junction, which is manufactured from a weakly magnetizable material and includes both a fixed permanent magnet that is stationary with respect to the sensor and configured to generate a magnetic field, and a sensor configured to detect movement of the magnetizable piston, and the movement monitor unit further comprises an electronics part which processes a signal received from the sensor produced as a result of a change in the magnetic field caused by the movement of the piston and forwards this processed signal to the control unit.