2. Experimental technique

Although many methods can be used to measure viscosity at room temperature, it is often the average working temperature that determines the choice of measurement method and the practical design of the equipment. The problems posed by experimentation at elevated temperatures can be compounded by other difficulties, particularly in the case of metals:

• high vapor pressure ;

• easy to contaminate at high temperatures ;

• lack of refractory purity and gas atmosphere cleanliness;

• vacuum degassing of refractories ;

• possible formation of an oxide film on the liquid surface;

• possible presence of precipitates in the liquid ;

• exact, reproducible viscometer...