When it comes to magnetic stirring, your choice in stirring bar can have a considerable impact on the effectiveness of an experiment. Though the setup may be simple, there are several factors to consider before choosing a stirring bar, such as size, shape, and material. Besides improving stirring efficacy, the correct choice can also minimize wear and abrasion of the bar coating. Consider the following three tips to find the best stirring bar first before your next experiment.
The Volume of Fluid Being Stirred
Regardless of the volume of fluid, it is essential to use a stirring bar that is small enough that it won’t collide with the sides of the vessel during stirring. For larger vessels, your experiment will require a larger stirring bar to yield more motion within the fluid, which also increases the mixing efficiency. With stirring bars as small as 8 millimeters wide and as large as 150 millimeters wide, 2mag has inventory to suit every experiment.
The Shape and Opening Size of the Vessel
Some vessels may have narrow openings despite very wide bottoms, which can limit your selection of stirring bars. Carefully examine the dimensions of the vessels necessary for your experiment before you purchase stirring bars. There are special circumstances to consider when a smaller bar may be appropriate even if the widest diameter of the vessel is relatively large. For example, a round-bottomed flask is not nearly as wide at its bottom-most point, which makes smaller bars a better choice for this type of vessel.
The Size of the Internal Drive
2mag stirring systems house cutting-edge stationary magnetic coils through which currents flow, producing the rotating electromagnetic fields that spin the stirring bar. When deciding on a stirring bar, its length should be roughly equal to the size of the magnetic field to avoid spinout – the act of a stirring bar becoming uncoupled from the internal magnet. Additionally, stirring bars that are substantially longer than the internal magnet will not be able to spin as quickly due to an increased amount of drag.
With so many factors to consider that play into the feasibility of a stirring bar, the process may vary between each laboratory application and may even require experimenting with multiple options. 2mag stirring bars are an essential component of all our stirring systems and we offer an extensive variety of sizes, shapes, and materials to meet the needs of your experiment. Contact us today to learn more about how our incredible selection can best serve your laboratory.