Laboratory magnetic stirrer - having permanent magnet attached to rotor with axial magnetisation giving better control of both long and short agitator elements

摘要

Magnetic stirrer has a permanent magnet attached to a shaft on an electric motor which is rotated. Above it in a vessel is a magnetic rod held in a magnetic coupling which causes it to rotate with the rotor. The permanent magnet on the rotor is magnetised along its axis so that the magnetic field lines along its surface leave vertically. The magnet is mounted on a disc of ferromagnetic material esp. iron or steel. This serves to screen the electric motor. Stirrer allows better control of the stirrer element, whether this be short or long, holding it firmly in the centre of the vessel and give better utilisation of the magnetic forces.