The Positherm-AL expendable thermocouple has been developed for direct and accurate temperature measurement in liquid aluminium and salts. The method is simple, effective and inexpensive. Immersion time is about 15 seconds.
The Positherm-AL thermocouple is supplied as a complete unit requiring no preparation or calibration before immersion; it simply has to be pushed onto a probeholder where it makes electrical contact to a polarized contact block. By means of an appropriate compensation cable, the lance has to be connected to a convenient analogue recorder, digital instrument or a portable temperature measuring instrument like Digilance.
Positherm-AL is typically used in Hall Heroult cells during aluminium electrolysis. Due to its low thermal mass, Positherm-AL readily equilibrates with the bath. This results in faster and more accurate measurements than those obtained with the classical type K, mineral insulated, metal-sheathed thermocouples. Application of type S (Pt 10% Rh/Pt) wires also adds to accuracy and makes measurements consistent from bath to bath.
Sensor: Positherm-AL
