<http://schema.org/description>
"&lt;p&gt;Generally the method required to verify a four-or five-axis, bi-rotary head machining center involves sophisticated laser interferometers and time consuming machine mapping to define and correct axis deviation from wear or other causes. For most shops, this calibration is done by an outside service.&lt;/p&gt;"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mmsonline.com/articles/in-house-measurement-for-bi-rotary-heads>