Patent ID: 7987609

Claim:
A measuring device, comprising: a transfer sleeve being a hollow cylinder, and comprising two end surfaces and a side surface; the transfer sleeve defining a transfer hole along the longitudinal direction thereof and perpendicular to the end surfaces, and the transfer hole passing through two end surfaces; the transfer sleeve defining a screw hole along the transversal direction thereof in the side surface and communicating with the transfer hole; an assist assembly screwed in the screw hole, and comprising a screw rod, a spring element, and a ball; the screw rod defining a receiving hole therein; the spring element and the ball are inserted into the receiving hole in sequence; and a caliper gauge comprising a base plate and two side plate extending upright from opposite edges of the base plate correspondingly; the distance L between the two side plates satisfying the following formula: L=H *tan α+ D *cos α where H is the height of the caliper gauge, D is the diameter of the sleeve, and α is the maximum acceptable inclined angle of a tube from a perpendicular direction of a base from which the tube extend.