ISO 230-2:2014 pdf free

ISO 230-2:2014 pdf free.Test code for machine tools – Determination of accuracy and repeatability of positioning of numerically controlled axes
It is recommended that the manufacturer/supplier offer guidelines regarding the kind of thermal environment acceptable for the machine to perform with the specified accuracy.
Such guidelines could contain, for example, a specification on the mean room temperature, maximum amplitude and frequency range of deviations from this mean temperature, and environmental thermal gradients. It shall be the responsibility of the user to provide an acceptable thermal environment for the operation and the performance testing of the machine tool at the installation site. However, if the user follows the guidelines provided by the machine manufacturer/supplier, the responsibility for machine performance according to the specifications reverts to the machine manufacturer/supplier.
Ideally, all dimensional measurements are made when both the measuring instrument and the measured object are soaked in an environment at a temperature of 20 °C. If the measurements are taken at temperatures other than 20°C, then correction for nominal differential expansion (NDE) between the axis positioning system or the workpiece/tool holding part of the machine tool and the test equipment shall be applied to yield results corrected to 20 °C. This condition might require temperature measurement of the representative part of the machine as well as the test equipment and a mathematical correction with the relevant thermal expansion coefficients. The NDE correction might also be achieved automatically, if the representative part of the machine tool and the test equipment have the same temperature and the same thermal expansion coefficient.
It should be noted, however, that any temperature departure from 20 °C can cause an additional uncertainty related to the uncertainty in the effective expansion coefficient(s) used for compensation. A typical minimum range value for the resulting uncertainty is 2 um/(m.°C) (see Annex A). Therefore, the actual temperatures shall be stated in the test report.
The machine and, if relevant, the measuring instruments shall have been in the test environment long enough (preferably overnight) to have reached a thermally stable condition before testing. They shall be protected from draughts and external radiation such as sunlight, overhead heaters, etc.ISO 230-2 pdf download.