hot plates and stirrers

Hotplates and stirrers are essential tools in any laboratory from a laboratory equipment supplier. They are widely used for numerous experimental applications. This guide explores their functions, types, and uses, along with core considerations for choosing the right equipment. 

What are Hotplates?

Hotplates are omnipresent in laboratories, providing a controlled heat source for experiments. These devices are available in different types, including magnetic and ceramic hotplates. When selecting a laboratory hotplate, it is important to consider features like temperature control, uniform heating, and types of experiments it will be used for.

What are Stirrers?

Stirrers are specialized devices used to efficiently mix substances in the lab. Available in various types, such as magnetic and overhead stirrers, each offers distinct benefits. Selecting the right stirrer depends on factors like the viscosity of the materials and the required mixing speed.

Applications of Stirrers and Hot Plates

Chemical Synthesis

Stirrers provide consistent mixing of reactants for efficient and precise chemical synthesis. In contrast, hotplates ensure uniform heating without open flames, which is important for controlling reaction parameters and creating materials with specific properties.

Biological Experiments

They are used for maintaining cultures, preparing media for bacterial growth, and in cell culture maintenance. Stirring gently avoids cell damage and is useful for tasks like enzyme assays and protein purification.

Analytical Chemistry

Magnetic stirrers ensure homogeneity in solutions for tasks like titrations and sample preparation, which increases the accuracy of analytical methods.

Pharmaceutical Research

These tools from lab equipment suppliers help develop and test new formulations and conduct dissolution studies.

How to Choose Stirrers and Hot Plates?

Accuracy and Stability

A standard analog hotplate stirrer offers affordability and simplicity but lacks precise control over temperature and speed. Units with bimetallic thermostats provide slightly improved heat regulation. 

In contrast, digital models with PID microprocessor control deliver high accuracy and stability, maintaining temperature within ±8°C and stirring speed within ±20 rpm, making them ideal for applications requiring precise, consistent performance.

Range and Uniformity

The top plate material —ceramic, porcelain, or aluminum —and the temperature control system determine a hot plate’s heating range and surface temperature uniformity.

Ceramic tops heat quickly and resist corrosion but offer less temperature uniformity and are prone to thermal shock, making them unsuitable for metal vessels or sand baths.

Porcelain tops provide better uniformity and corrosion resistance, though they may flex at high temperatures. Both ceramic and porcelain surfaces enhance sample visibility.

Aluminum tops deliver the best temperature uniformity and stability (±10°C) and are ideal for larger surfaces or multiple vessels. However, they are more prone to corrosion and more complex to clean.

Volume

Stirrers, hotplates, and combination units are available in a wide range of sizes and configurations, from compact single-vessel models to large-capacity, multi-unit systems.

In the end, choosing the right stirrers and hotplates depends on your lab’s requirements for precision, temperature control, and capacity. Considering factors like accuracy, heating uniformity, and material ensures reliable performance and consistent experimental results.