About: http://webisa.webdatacommons.org/21296430

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	The calibration fixture consists of a tetrahedron built from a material that is mechanically stiff and thermally stable such as invar or carbon/epoxy.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com