Rolling mill gap sensor

A rolling mill comprising a first and a second roll that rotate on parallel axes and that have cylindrical working faces which form a roll pass through which material travels to determine the gauge of said material, sensors for determining movement on the rolls toward and from one another including a first sensor that is adjacent to a circumferential area of said first roll at a location immediately adjacent to a center line extending through the axes of said rolls but axially spaced from the surfaces of the rolls that contact with the material that travels through the roll pass, a second sensor that is adjacent to a circumferential area of the second roll at a location immediately adjacent to a center line extending through the axes of said rolls and axially spaced from the first sensor and from the surfaces of the rolls that contact with the material that travels through the roll pass, said circumferential area of each of said first and second rolls being axially spaced from the corresponding circumferential area of the other roll and being substantially coaxial with its roll and of the same circumference as the cylindrical working face of its roll and located in position to be ground whenever the working face of its roll is ground and as part of the grinding operation whereby any eccentricity ground into the working face is duplicated in said circumferential area of the roll, one of the rolls having a circumferential recess between its working face and its circumferential area that is adjacent to one of the sensors for providing clearance for the sensor that is adjacent to the circumferential area of the other roll, a frame connected with the respective sensors, a transducer operated by relative movement in said frame, and apparatus responsive to signals from the transducer.