Key Components of Magnetic Stirrers

What is a Magnetic Stirrer?

Dating from 1917 magnetic stirrers have evolved and been perfected over the years to perform critical mixing functions in the research lab when low-viscosity liquids are being processed in beakers and flasks to 10 liters in capacity.  We at CAT Scientific call magnetic stirrers the unsung hero of your laboratory thanks to the many refinements and enhancements introduced.  To help you understand what goes into these instruments we offer our list of key components of magnetic stirrers.

Magnetic Stirrer Glossary of Terms | Simplifying the Complex

Although there are hundreds of terms associated with magnetic stirrers and their operation, the following have been carefully selected by CAT Scientific. We believe these are the most essential terms all operators should understand.

• Bar Magnet| Also referred to as Stir Bars, these items come in a variety of shapes and sizes. Bar magnets are magnetic (no surprise here) and are submerged in the beaker or flask.  They are powered by a rotating magnet in the base of the stirrer in order to perform the stirring function.  Bar magnets have easily cleaned inert coatings to avoid contaminating the solution.
• Beaker| The actual glass container, or vessel, that holds the solution to be mixed. Beakers are available in a variety of sizes based upon the quantity and type of liquid to be mixed. While sizes vary, their appearance is relatively uniform – straight sides with a fully opened top. See Also – Flask
• Drive Magnet| The motor-powered rotating magnet within the magnetic stirrer base that rotates the bar magnet.
• EEPROM | Electronically Erasable Programmable Read-Only Memory. Operational instructions/parameters are input via the device control panel – either through a keypad or an encoder wheel. Operational parameters are automatically safeguarded to prevent stirring/heating solutions beyond what the user selects.
• Flask | Also referred to as a Beaker, this glass container holds liquid solutions during the mixing process. These containers are characterized by having a wider base with inward sloping sides. The opening at the top is narrower than the base. CAT Scientific magnetic stirrers can also accommodate round bottom flasks.
• Flea | A casual term used to describe Bar Magnets. Coined by Edward McLaughlin of the Torpedo Experimental Establishment in Greenock, Scotland in the late 1940s, this term came to fruition after McLaughlin witnessed how bar magnets can jump about if the rotating magnet is driven too fast.
• Fuzzy Logic| Defined as way to measure reasoning that is approximate rather than fixed and exact. A standardized logic designed to swiftly heat solutions without overshooting the target temperature. Also refers to sustaining temperature stability during operation.
• Hotplate | The actual heating mechanism within magnetic stirrers on which beakers and flasks are set. They are available in a variety of materials including CERAN, stainless steel and aluminum.
• Hotplate Temperatures| The physical temperature at which the hotplate is set. CAT Scientific magnetic stirrers offer dynamic and precise temperature control by allowing users to set temperatures in 1℃ Depending on magnetic stirrer model, temperatures may range from 40℃ to 500℃. CAT Scientific also offers magnetic stirrers without heating capabilities.
• Microprocessor Control| This term refers to the digital technology designed to monitor and control the operational parameters of the device. CAT Scientific magnetic stirrers also include the RS232 Interface, which enables networking/communication between the magnetic stirrer and other laboratory equipment, printers and computers.
• Mixing Speed| The actual speed at which the bar magnet rotates. Speeds are controlled by the rotating magnet. Operational parameters vary based on device model, but most offer precise mixing speeds between 60 and 1,600 RPM.
• Mounting Bracket| The adjustable assembly designed to hold the temperature probe in place against the beaker.
• PT-100 Probe| Also referred to as the Platinum Resistance Temperature Probe, this accessory continually monitors and measures solution temperatures. Should temperatures exceed safety parameters, it shuts down the device.
• RS232 Interface| The digital network that connects the magnetic stirrer to a computer or printer with the primary purpose of archiving results.
• Safety Parameters| Read more about CAT Scientific magnetic stirrer safety features and parameters in our article Safeguarding Innovation – CAT Scientific Magnetic Stirrer Safety Elements.
• Set and Actual Values| The variable operation parameters set by users via the encoder wheel of keypad.
• Soft Start| When activated, the magnetic stirrer starts operation slowly and precisely increases stirring speed to prevent splashing liquid contents.
• Temperature Ramp| Eliminates “hot spots” in the mixing solution by evenly heating the ingredients via precise hotplate temperature control and the rotating flea.

In Closing

As always our goal at CAT Scientific is to not only provide you with innovative solutions for modern applications, but also to assist in growing your knowledge of this dynamic and ever-evolving industry. We hope this glossary of essential terms regarding magnetic stirrers assists in your usage of our products. Of course, if you’re still in need of assistance or have a specific question, please don’t hesitate to contact us.