An overhead stirrer is a laboratory device used for mixing, homogenizing, suspending, and recirculating large volumes or high-viscosity substances, which typically can't be handled by a magnetic stirrer. The stirrer itself is placed atop a either a plate stand or an H-stand, depending on the weight and power level of the stirrer, as well as the type of container that is to have its contents stirred. Clamps of various sorts attach the stirrer to the stand and the container to the mixing platform. Determinants for choosing an overhead stirrer include how large of a quantity needs to be mixed, the viscosity of the substance to be mixed, the required speed range, the programming and integration functions, and the sensors it includes, including one that allows for the monitoring of reaction progress as a function of viscosity change.
- Gilchrist, A.J. (2022). Making Quality Cosmetics: Good Manufacturing Practice and ISO 22716:2007. Royal Society of Chemistry. pp. 101-103. ISBN 9781839165146. https://books.google.com/books?id=iUKLEAAAQBAJ&pg=PA101.