recorded at the time t 4 if this is not the case the control device concludes that there is a break in the transfer strip this design variant has the advantage that it manages without any predefinition or calculation of reference pressure values and detects a web break by using the simple break condition that a pressure value recorded at a later time is not smaller than a pressure value recorded at an earlier time furthermore a third design variant for detecting a break of the transfer strip during tail widening is conceivable in which the break is detected on the basis of the comparison of two pressure values p 6 p 7 recorded at a short time interval at t 6 t 7 although in this case too the use of a break condition according to the second design variant is in principle possible it would be possible for erroneous triggering of a break signal to occur in the case of pressure measurements following one another closely in time because of random pressure fluctuations within the suction box 24 as can be seen in fig4 this is because the reference pressure values p 6 and p 7 are also relatively close to each other and their difference can lie in the range of the order of magnitude of random pressure fluctuations according to the third design variant a web break signal is therefore generated only when the pressure p 7 measured at the time t 7 exceeds the pressure p 6 measured at the earlier time t 6 by at least a predetermined threshold value s.