Between overhead stirrers and magnetic stirring systems, both options are best suited for different scenarios. Making the choice isn’t simple because there are a variety of important factors to weigh, such as vessel shape, heat required, type of mixing, and more. Continue reading for an informative look into each factor you need to consider before choosing between a magnetic stirrer or overhead stirrer.
Sample Volume
Overhead stirrers are often used for mixing large volumes of samples, such as 100, 200, or even 1,000 liters. On the other hand, magnetic stirrers are excellent at stirring smaller sample sizes. The average magnetic stirrer can handle up to 20 liters of volume but 2mag offers a wide variety of magnetic stirrers that can stir volumes up to 1,000 liters. When choosing a magnetic stirrer, be sure to also take into account an appropriately sized stirring bar to mix your sample without decoupling or spinning out.
Vessel Shape
Knowing which vessels you’ll be using is key to deciding between overhead and magnetic stirring. Narrow openings may make it unfeasible for overhead stirrers to access the sample inside your vessel, which is where magnetic stirrers shine. Additionally, it is easy for magnetic stirrers to mix samples in closed vessels that may be necessary to avoid contamination or perform a process under vacuum. Overhead stirrers require special bearings to facilitate this process, whereas magnetic stirrers are easily capable of such a project.
Heat Requirements
In order to introduce heat to a sample, overhead stirrers often require a water or oil bath. This is effective for larger samples because it applies heat to a greater surface area of the vessel. However, a water bath is more likely to introduce contamination to samples. Instead, consider a magnetic stirrer with built-in heating functionality for a solution that is both compact and affordable. 2mag stirring hotplate systems are made from resistant aluminum alloy and offer a maximum heating temperature of over 200 degrees C.
Type of Mixing
Both overhead and magnetic stirrers provide numerous options of mixing types, such as axial, radial, or tangential flow. However, gaps exist in the coverage offered by both, where one may excel over the other. For example, overhead stirrers excel at stirring samples that are high-shear or high-viscosity. Conversely, magnetic stirring systems are the ideal choice for applications like blending liquids, dissolving powder, and heat transfer.
There is much to consider when deciding between a magnetic stirrer or an overhead stirrer. For experiments in which you would be best served by magnetic stirring systems, give 2mag a call. Our magnetic stirrers are guaranteed to have outstanding long-life quality with no wear and tear or maintenance. We developed our stirring systems for hard daily lab use and uncompromising continuous operation – simply contact us to learn more about the best fit for your needs.