Assertion: sulfur hexafluoride | /r/HasProperty | the tracer gas
Facets:
Source sentences:
text: Sulfur hexafluoride was the tracer gas used in the first roadway air dispersion model calibration; this research program was sponsored by the U.S. Environmental Protection Agency and conducted in Sunnyvale, California on U.S. Highway 101.
text: Sulfur hexafluoride (S[F.sub.6]) is the tracer gas used.