An apparatus for detecting streaks in a moving sheet of material utilizes the signal generating and processing means of an existing spot/hole detection system which provides a series of spot measurement signals generated sequentially as a machine direction series of cross-machine sets and assigns a cross-direction location to each signal. Means are provided for calculating an exponential average of the signals for each of the cross-machine locations. This average is compared with a predetermined standard and an output signal, including a cross-machine location, is generated when the average exceeds the standard.