Stirring is vital to many laboratory experiments, and having the right equipment can make all the difference. Lab stirrers come in various shapes, from simple magnetic stirrers for small volumes to large-volume overhead stirrers for more complex tasks. Each type has its own unique qualities that make it better suited for specific applications than others.
In this guide, we will discuss the different types of lab stirrers available and their respective advantages so you can choose the one best suited for your lab needs.
What are stirrers used for in a laboratory?
Lab stirrers mix or agitate substances in laboratory experiments. Stirring helps to ensure that ingredients are evenly distributed throughout a solution, which is essential for getting accurate results from an experiment. For example, stirring helps to dissolve solids in liquids, blend two immiscible fluids into one homogenous mixture, or suspend solid particles in a liquid medium. Additionally, many laboratory stirrers have adjustable speeds to be set at the optimal rate to mix different solutions with different viscosities or have heating elements
Magnetic Stirrers
Magnetic stirrers use a magnetic bar and spinning motion to create a vortex inside the container, evenly distributing the solution and creating a homogeneous mix. These stirrers are great for small-scale applications like making buffers or mixing reagents, requiring minimal effort from the user. The two main types of magnetic stirrers available are hotplate stirrers and analogue stirrers:
- Hotplate Stirrers: Hotplate stirrers are designed for larger volumes and can be set to specific temperatures for more precise control over stirring speed and temperature. They come in a variety of materials, which again are used for differing applications:
- Ceramic hotplate stirrers are ideal for applications where very high temperatures are required or contain corrosive materials. Ceramic hotplates must only be used with glassware and not metal containers.
- Aluminium hotplate stirrers provide excellent heat transfer and reach higher temperatures than ceramic models (up to 450°C). They are also more robust and can withstand accidental knocks. Metal containers can be used with an Aluminium hotplate stirrer.
- Analog Stirrers: Analog stirrers are ideal for stirring small volumes of liquids, such as solutions in test tubes or beakers and do not require additional heat. They create a vortex with the spinning bar and are usually adjustable so you can change the stirring speed. These stirrers are powered using an AC/DC adapter, making them very reliable and easy to use.
Overhead Stirrers
Overhead stirrers are large-volume stirring devices often used for more complex mixing tasks. They typically consist of a motorised drive unit connected to the top of the stirring shaft or impeller. This shaft is then inserted into the container to create a homogeneous mixture. The type of overhead stirrer you need will depend on your application, as there are several different varieties available:
- Planetary Stirrers: Planetary stirrers feature multiple blades that rotate in different directions and at varying speeds, allowing for more efficient mixing than single-blade models. These are great for dispersing and suspending materials, such as powders or granules in liquids.
- Anchor Stirrers: Anchor stirrers use one or two blades that act like anchors when submerged in liquid. This type of stirring action creates more turbulence than other overhead stirrers and is ideal for applications requiring increased agitation.
- Flexible Impeller Stirrers: Flexible impeller stirrers feature paddles that flex to accommodate different vessel shapes and sizes while providing efficient mixing action. These are great for applications where odd-shaped vessels or highly viscous fluids must be stirred.
- High-Speed Dispersers: High-speed dispersers use high-speed rotation to quickly blend components, making them well suited for emulsifying viscous substances or dispersing solids into liquids. These models come with various attachments, such as choppers or homogenisers for specific needs.
- Rotor/Stator Stirrers: Rotor/stator stirrers use spinning blades within an outer casing, creating an extremely high level of turbulence ideal for deagglomeration and homogenisation tasks. Depending on your requirements, these models can easily handle large volumes and high viscosities and come in stationary and mobile designs.
No matter what type of application you need it for, a reliable lab stirrer is essential to ensure accuracy in your experiment results. With the most suitable model, you can get consistent mixes quickly and efficiently without worrying about uneven results or wasted time due to manual stirring methods. No matter what your stirring needs are, Techmate has you covered with a wide range of magnetic and overhead stirrers. If you are unsure of what you might require, you can always contact us and we can recommended the best stirrer for your needs.
