[ Apparatus for analyzing sulfur gas; ] plastometers; dilatometers; drying [ and microwave ] ovens for laboratory use; coal hardness testing machines to test the grindability of coal; [ hand-operated laboratory tools for manipulating laboratory samples of coal; ] furnaces for laboratory use with ash; automated testing instruments for determining volatility of coke and coal; electrical controllers for furnaces; temperature indicator probes; testers for coke drum tumblers