About: http://webisa.webdatacommons.org/17867191

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	Could it be hiding under the plenum?I will retest using your negative and positive method and see if I get anything other than the 0.4 volts I got with my test meter using the positive instead of negative way round.
http://www.w3.org/ns/prov#wasQuotedFrom	justanswer.com