A device and method for inspecting the deposition of hot melt onto an object to be assembled. A comparison is made between sensed images of the object after application of the hot melt and a predetermined standard to determine if the construction integrity of the object made with the hot melt is within the range established by the standard. Composite images from a sensor operating in the infrared band and another sensor reveal physical features of the object, as well as provide registration information about the placement of the hot melt on the assembled object. Composite images also present a way to visually ascertain ongoing or past production operations in order to trace problems with the raw material used for the object, as well as for the construction process of the object with the hot melt.