DIN ISO 230-2:2011-11

The purpose of ISO 230 is to standardize methods for testing the accuracy of machine tools, excluding portable power tools. This part of ISO 230 specifies test procedures used to determine the accuracy and repeatability of positioning numerically controlled axes. The tests are designed to measure the relative displacements between the component that holds the tool and the component that holds the workpiece. Since measurement uncertainty needs to be stated with the measurement results, a description of the estimation of the measurement uncertainty for the determination of the accuracy and repeatability of positioning has been added as Annex A. It is believed that, with this addition, the relevant contributors to the measurement uncertainty are able to be recognized more easily and reduced more efficiently. The supplier/manufacturer should provide thermal specifications for the environment in which the machine can be expected to perform with the specified accuracy. The machine user is responsible for providing a suitable test environment by meeting the supplier/manufacturer's thermal guidelines or otherwise accepting reduced performance. An example of environmental thermal guidelines is given in ISO 230-3, Annex C. A relaxation of accuracy expectations is required if the thermal environment causes excessive uncertainty or variation in the machine tool performance and does not meet the supplier/manufacturer's thermal guidelines. If the machine does not meet its performance specifications, the analysis of the uncertainty due to the compensation of the machine tool temperature, given in A.2.4 of this part of ISO 230, and the uncertainty due to the environmental variation error, given in A.2.5, can help in identifying sources of problems.