About: http://webisa.webdatacommons.org/94529861

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 transducer may be provided with a collumnating device such as a tube so that the beam can be considerably narrowed, if such is desired.
http://www.w3.org/ns/prov#wasQuotedFrom	google.co.uk