A method and apparatus for monitoring {HEAD ~ a liquid} undergoing anaerobic fermentation in {TAIL ~ a vessel} is disclosed 
A method and apparatus for monitoring { HEAD ~ a liquid } undergoing anaerobic fermentation in { TAIL ~ a vessel } is disclosed
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH