Abstract: A tensioned metal strip over an apparatus for measuring tension that only has a roller rotatable about an axis transverse to the direction and having a substantially cylindrical outer surface engaged generally tangentially by the strip, a radially shiftable tension-measuring bar set in the roller, extending generally only angularly of the axis so as to lie in a plane substantially perpendicular to the axis, and having an outer surface generally flush with the roller surface. Sensors between the bar and the roller for measuring radial deflection of the bar. The apparatus, when used to determine planarity, further has a planarity-measuring bar also set in the roller, extending at an acute angle to and across a respective plane perpendicular to the axis, and having an outer surface generally flush with the roller outer surface. Other sensors between the planarity-measuring and the roller measure radial deflection of the planarity-measuring bar.