About: http://webisa.webdatacommons.org/107248124

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	To calibrate the sensor, first zero gas is applied (i.e., pure air, with no methane or other contaminants) through the temporary gas supply tubing 603.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com