Silicon nitride thermocouple protection tube Using pure silicon nitride thermocouple protection tubes, the temperature transmission and induction are more rapid and accurate with its high strength and thin thickness. With excellent oxidation resistance and corrosion resistance, the service life of silicon nitride thermocouple protection tube is more than 5-8 times that of NSIC tubes.At the same time, silicon nitride is not infiltrated with the non-ferrous metal melt and it is not easy to form slags and is easier to maintain