Method, measuring arrangement and system for measuring an internal contour, in particular an internal thread on a sleeve or a sleeve end of a pipe

A method for measuring an internal thread (2) on a sleeve or a sleeve end of a pipe (1) using a measuring arrangement having at least two sensors (3, 4), including a first sensor (3) being an inner sensor, and a second sensor (4) being an outer sensor, the method comprising:

• arranging the first sensor (3) radially at a defined distance from the second sensor (4) with respect to a longitudinal axis of the pipe (1) such that the first sensor (3) detects an inside of the pipe (1) and that the second sensor (4) detects an outside of the pipe (1);
• scanning an internal contour in a first measurement run along a first measuring section parallel to a longitudinal axis of the pipe (1) by the first sensor (3);
• determining an external diameter of the pipe (1) as a reference for a measurement signal of the first sensor (3) by measurement signals of the second sensor (4);
• and
• storing and/or processing detected measurement values by electronic data processing for mapping a thread profile.

A measuring arrangement for measuring an internal thread (2) on a sleeve or sleeve end of a pipe (1), comprising:

• an optical inner sensor (3);
• and
• an optical outer sensor (4), the optical inner sensor (3) being arranged at a defined radial distance from the optical outer sensor (4),
• wherein the measuring arrangement is linearly movable along a measuring section defined in a measuring axis (6) during a measurement run and arranged rotatably around the measuring axis (6).