The present invention is capable of measuring the displacement of efficiently wall thickness and the inner and outer surface of the pipe, to provide the thickness and the inner and outer surface displacement measuring device of evaluable tubes swell of and thus the inner and outer surfaces of the tube.
A measuring apparatus according to the present invention 100 includes a shaped member 1 co comprising a first arm portion 11 and the second arm portion 12, at the open end of the U-shaped member, a first arm portion in a first contactor 2 mounted, a contact type displacement meter 3 having a second contactor 32 attached to the second arm portion, co as the first contactor is in contact with the inner surface of the pipe P and biasing means 4 for urging the shaped member, the displacement gauge 5 for measuring the displacement of the U-shaped member, a moving means 6 for relatively moving integrally the shaped member or the like co in the axial direction of the pipe , calculates the thickness of the pipe on the basis of the displacement measurements by contact displacement sensor, calculates the displacement of the inner surface of the basis of the displacement value measured by displacement meter pipe, tube based on the displacement measurements by contact displacement sensor and displacement gauge It includes the calculating means 7 for calculating the displacement of the outer surface, a.
.FIELD 1