About: http://webisa.webdatacommons.org/418799209

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	FIG. 2 is an illustration of the relative voltage levels of the output signals O1, O2, O3 and O4 and the locations of the sonic image 2 in which the voltage levels are indicated by hatched area.
http://www.w3.org/ns/prov#wasQuotedFrom	freepatentsonline.com