System for monitoring the tension in a belt, in particular in a cargo belt

System for monitoring the position of a belt around an object, comprises a belt unit (16) with a force sensor (20) for measuring the tension of a belt around an object, a transmitter for cable or wireless transmission of a tension measurement signal and a power supply (26). A display unit (18) has a receiver (22) for the tension measurement signal and a display device for optical and or acoustic display of the tension information.