Abstract: A rolling or continuous casting and rolling mill facility includes a roll set comprising working rolls defining a roll gap therebetween and support rolls, at least one of the working rolls and the support rolls having coaxial reduced diameter barrel portions defining measurement surfaces thereon; a measuring element for determining the roll gap by measuring a distance between the measurement surfaces, comprising a measurement head and a contact-free double sensor positioned on the measurement head; and an element for moving the measurement head between a working position wherein the double sensor is positioned in a rolling plane drawn through axes of rotation of the working rolls and aligned with the measurement surfaces and a rest position wherein the measurement head and double sensor are withdrawn from the rolling plane.