An apparatus and method for scanning a surface of an article moving along a travel path axis provide a compact sensor configuration. A first sensor unit has a first sensing field transversely directed toward the travel path axis and defining a first scanning zone. A second sensor unit has a second sensing field transversely directed toward the travel path axis and defining a second scanning zone. The first and second sensing fields are crossing one with another at a location sufficiently remote from the first and second scanning zones so as to not adversely affect the generation of sensor output data, while providing a compact arrangement of sensor units.