A system and method for measuring an inside diameter of a pipe to determine if it exceeds a predetermined value using a plurality of fingers operatively connected to a spring. When in a fully extended position, the distance between opposite fingers is the predetermined value. The fingers are pivotable between a starting position, through the fully extended position, and to a failing position. In the starting position, an outer end of each finger engages an inside surface of the pipe to compress the spring. If the diameter exceeds the predetermined value as the system moves through the pipe, the pipe inside surface will no longer engage the fingers, which releases the spring causing the fingers to pivot to the failing position, where they remain until the system is removed from the pipe and manually reset.