ISO 13041-7:2004 describes a method of checking the contouring performance of turning centres (or numerically controlled turning) by conducting circular tests and by evaluating the radial deviation F, and circular deviation G, in accordance with ISO 230-4:1996.

The concept of checks by circular tests described in ISO 13041-7:2004 is to verify the circular movement only in one position per coordinate plane of the machine, at only one feed rate, and to repeat the test once in the opposite contouring direction.