High temperature tube furnace with MoSi2 heating elements for small lab-scale metallurgical experiments: high-temperature materials interactions, slag-metal equilibria, inclusions, interactions with refractory, ... The tube is gas-tight so that experiments can be conducted under protective or active atmospheres. Argon is deoxidised by leading it over magnesium at 500°C. The partial oxygen pressure (pO2) can be set by means of two mass flow controllers that control the CO/CO2-ratio. Samples can be taken and additions can be made during experiments and oxygen can be measured in the high temperature zone. A viscosimeter can be installed on top and measure the viscosity of molten materials. The crucible can be taken out through the top flange with a hook or can be quenched via the bottom flange. A programmable PID-controller controls the temperature of the furnace.