is only partially covered this is the sensor for which the following expression is minimum u u max u min 2 u max is the output voltage of an uncovered sensor and u min is the output voltage of a completely covered sensor calculations referred to above are performed to advantage by using a computer system not shown in this way it is possible to obtain a very accurate value for the position of the strip edge of metal strip 1 this value can be used to advantage for further control of the mill train in addition the measured values of sensor 21 whose measurement area 25 is not covered completely by the metal strip are corrected to advantage so that the measured values of all sensors 21 22 23 24 can be used for determining the tensile stress in metal strip 1 the amplitude of the periodic deflection of metal strip 1 is advantageously analyzed to determine the tensile stress an example of how the tensile stress is determined from measured values for deflection of metal strip 1 is given below for additional advantageous devices for measuring tensile stress distribution in metal strip 1 such embodiments are illustrated in fig5 and 6 fig5 shows the embodiment according to fig1 supplemented by an additional measurement device 7 measurement devices 7 and 8 supply.