A temperature sensor 42 is provided in {TAIL ~ a furnace} 11, measuring temperature above a molten liquid 24 put in a crucible 12 to check {HEAD ~ proceedings} of evaporation of oxygen vaporized from a free surface 44 of the molten liquid 24 
A temperature sensor 42 is provided in { TAIL ~ a furnace } 11 , measuring temperature above a molten liquid 24 put in a crucible 12 to check { HEAD ~ proceedings } of evaporation of oxygen vaporized from a free surface 44 of the molten liquid 24
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH