Temperature is a critical variable in chemical, biological, and physical reactions. Heating is often required for sample digestion, extractions, purifications, measurements, and other applications.
Laboratory technicians often rely on specialized equipment to generate heat to facilitate these reactions. These include Bunsen burners, hot plates, heating mantles, ovens, furnaces, incubators, and baths. For large-scale reactions, larger laboratory equipment is needed. In this article, we will describe the working principles of hot plates and reaction blocks and vacuum, pass-through, and drying ovens.
Hot Plates
Hot plates are a simple piece of laboratory equipment consisting of an electrically heated flat surface connected to controls that allow temperature variation. Hot plates are suitable for heating solutions above 100oC (212oF) and are safer to operate than open-flame heaters1. However, older hot plates pose a higher risk of an electric spark arising from the on/off switch or the thermostat.
A related laboratory equipment is a hot plate stirrer that keeps liquids circulating during heating with built-in timers and temperature sensors for added safety and precision.
Reaction Blocks
Reaction blocks are heating laboratory equipment capable of holding one or more flasks, tubes, or vials (within a block) while providing uniform heating for multiple reactions. They enable temperature homogeneity (±1°C) for reactions reaching up to 300°C2. These blocks may have a built-in heater or can be used in conjunction with a hot plate stirrer.
Reaction blocks accelerate reactions while providing a cleaner and safer lab environment.
Vacuum Ovens
Vacuum ovens are helpful for drying applications in the absence of heat. Delicate components, such as semiconducting microchips, often require the rapid removal of water from their surface while avoiding complications created by oxidation in air. A tightly sealed door gasket ensures that vacuum levels are maintained in a vacuum oven.
Vacuum ovens enable precise control of pressure, airflow, and temperature during the drying phase. This laboratory equipment has a wide range of applications, including sterilization, solvent separation, moisture sampling, and age testing.
Pass-Through Ovens
A pass-through oven is heating laboratory equipment designed to minimize cross-contamination during sample transfer between clean and grey rooms and other environments. Pass-through ovens feature doors on both sides of their heating chamber for rapid sample pass-through, with fanned convection heating for temperature uniformity.
These ovens are also fitted with control technology, such as a digital timer, graphical displays, data loggers, and USB ports. They operate at temperatures reaching 250oC approximately, with chamber capacities reaching about 750 L. This laboratory equipment is used for heat resistance tests, ageing and conditioning, hardening and drying, tempering, and others.
Universal Heating and Drying Ovens
As the name implies, universal heating and drying ovens cover many applications, including material testing, ageing, drying, tempering, hardening and heating. This versatile laboratory equipment is best suited for heating applications above 50oC up to 300°C approximately. Together with natural or forced convection, all-round heating ensures excellent heat transfer and temperature homogeneity.
Within heating laboratory equipment such as universal drying ovens, optimum temperature distribution ensures rapid drying while allowing precise control of reactions. Universal drying ovens enable:
- Precise and homogeneous temperature control
- Control over air and heat transfer rates
- The prevention of temperature fluctuations
- A programmable electronic control interface
- An easy to clean, corrosion-resistant chamber
Universal heating laboratory equipment is used for:
- Sample preparation
- Measuring humidity content
- Curing silicones and adhesives
- Comparing nanostructures
- Tempering components
- Ageing plastics and metals
- Testing materials
- Degassing epoxies
- Drying electronic components
Laboratory Equipment by Delta Scientific
Delta Scientific supplies a wide range of laboratory equipment from world renowned brands for scientific research. Among our core product portfolio is a range of Memmert heating and drying ovens, which forefront simplicity and ease-of-use in lab-based settings. All Memmert systems centre intuitive operability and innovative communications with modern interfaces. Refer to our heating and drying equipment page to find our full range of Memmert solutions.
References
- Baylor University. Section 7I: Laboratory Equipment. [online] Available at: https://www.baylor.edu/ehs/index.php?id=92739
- University of Colorado. Dry Bath/Heat Blocks. [online] Available at: https://www.colorado.edu/lab/even/instrumentation/sample-prep-heating/dry-bathheat-blocks