Just curious. Does anybody measure temperature ? Infrared pyrometer, thermocouple ? I kick off. I use a type S (K is too unstable and not high temperature resistant) thermocouple sheathed in alumina but can only measure swirling air/ gas temperature around the crucible. This TC is very durable. I have no means of measuring metal temperature as the couple itself dissolves in the metal (when immersed without sheathing) or the sheathing gets wetted and when pulling it, the wetted sheathing freezes with a thin layer of metal on it. Using an infrared pyrometer cannot be used on bare metal because of the low emissin factor, so I can only measure on the slag layer which is only an indication (+/- 50 C) of the metal temperature. I saw in a thread of Petee716 http://forums.thehomefoundry.org/index.php?threads/first-iron-melt-real-time.1101/page-2 that he talks about "The stain is spit (poor man's pyrometer).". I once heard a similar story about that in the past iron casters spitted on the liquid iron and inspected how the spit reacts which can be an indication of the temperature. I don't believe it, because the spit vaporizes before reaching the crucible. Or is this true ?