About: http://webisa.webdatacommons.org/114223507

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	So, even if any material except a metallic comes between the RF oscillation proximity sensor and the object, a proximity switch is able to detect the object to detect without interference with the material.
http://www.w3.org/ns/prov#wasQuotedFrom	freshpatents.com