and those local regions where the pattern appears to be distorted are identified application_number US 70089276 A description the novel inspection method may be practiced as a table top operation performed in a booth to shield the equipment and the operator at least partially from normal ambient lighting as shown in fig1 and 2 the equipment includes a diffuse light source and a translucent pedestal thereon the light source shown is a shallow box 11 enclosing several fluorescent lamps 13 set in a parallel array the upper wall 15 as shown of the light box 11 is a translucent plastic plate with this arrangement diffuse light passes upwards out of the box 11 the pedestal 17 is a translucent plastic plate that carries a pattern 19 hereinafter described on its upper surface as shown the upper surface of the plastic plate constituting the pedestal 17 which carries the pattern 19 has the shape of the inner surface of the window to be inspected the pedestal 17 is supported on a rectangular frame 20 which has four legs 21 one in each corner of the frame 20 that rests on and is preferably physically attached to the upper wall 15 of the light box 11 the pedestal 17 is of such length and width that it fits within the faceplate and overlies the entire image viewable portion thereof but may.