MEASURING AREA

To nondestructively measure the area of a relatively flat object, a length increment encoder controls the signals generated by a width sensing array as a scanning section containing the width sensing array is moved relative to a fixed reference over the object to be measured in a manner dependent on increments of length moved by the scanner and independent of the velocity of the scanner so that the signals from the width sensing array are integrated with respect to length, with the signals being accumulated in a counter to represent the area of the object. In one embodiment, an optical system provides an image of a line of width on the object being scanned, which image is reduced and projected onto a sensing array to improve the resolution of the area measuring instrument and to reduce its bulk.