About: http://webisa.webdatacommons.org/426306479

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	When a customer moves across the beam, thus interrupting it, the photosensor detects the change in the amount of incident light and may sound an audible alarm, such as ringing a bell.
http://www.w3.org/ns/prov#wasQuotedFrom	google.es