Powerful laboratory stirrer for high viscous applications and intensive mixing for quantities up to 150 l (H2O). It automatically adjusts the speed within the range of 0/6 – 2000 rpm (two speed ranges) through microprocessor controlled technology. The control stirrer comes equipped with a RS 232 and a USB interface to control and document all parameters. An integrated torque trend display is provided for the measurement of viscosity changes, as well as integrated safety circuits ensure automatic cut-off in an anti-stall or overload conditions. Continuous comparison of shaft to desired speed is performed and variations are adjusted automatically. This ensures constant speed even with changes in viscosities of the sample.