This part of ISO 230 defines three tests, which are:
- environmental temperature variation error (ETVE) test;
- thermal distortion test caused by rotating spindles;
- thermal distortion test caused by moving linear axes.
The tests for thermal distortion caused by moving linear axes (see clause 7) are applicable to numerically controlled (NC) machines only and are designed to quantify the effects of thermal expansion and contraction of the axes on positioning accuracy and repeatability. For practical reasons, the test methods described in clause 7 apply to machines with linear axes up to 2 000 mm in length. If they are used for machines with axes longer than 2 000 mm, a representative length of 2 000 mm in the normal range of each axis should be chosen for the tests.
It should be noted that it is not foreseen to determine numerical tolerances for the tests described in this part of ISO 230.