Abstract: A tensiometer and method for measuring tension measure strain produced by a lateral displacement of a flexible line under tension. A block having a cylindrical cavity following a curved path is used to displace the flexible line. Tension in the line produces compressive stress within the block in the direction of the radius of curvature and tensile stress in the direction opposite the radius of curvature. A resistive strain gauge is used to measure strain due to either the compressive stress or tensile stress and a measurement circuit generates either a graphical display in accordance with standard tension measurement units, an audible or visual alarm when tension exceeds a predetermined threshold, or both.