A hotplate is a basic device that can be found in any lab and is primarily designed for heating liquid media
In many cases it is combined with a magnetic stirrer for uniform temperature and good homogeneity of the liquid.
Uses of Lab hot Plates
Magnetic stirrers without stirrers are used for a wide range of laboratory and industrial uses: heating liquids, utensils, parts, slides and more.
The correct choice of laboratory hot plate depends on the user's requirements:
-Maximum required working temperature
-Plate size required
- Required temperature control
-What is the use, what are the materials, the parts that heat
- The required temperature uniformity
Maximum Working Temperature Required
- For working temperatures up to 300-400 Celsius, use plates made of aluminum.
They have excellent thermal conductivity. The larger they are, the better the temperature uniformity in them.
Temperature uniformity improves as you get closer to the center of the plate because the edges of the plate have heat leakage.The temperature of aluminum hot plates is limited to 370 degrees Celsius, above 400 degrees Celsius the aluminum begins to deform.
For working temperatures up to 400-500 degrees Celsius, use plates made of iron or plates made of ceramic glass.
The processing of iron plates is less smooth than that of ceramic glass plates.Ceramic glass is resistant to chemicals but can break as a result of mechanical blows.
For working temperatures up to 600 Celsius work with titanium plates.
- Hot Plate size
The larger the hot plate, the larger the work area and the higher the power consumption,
The size of the small plates:
115 * 115 mm, 175 * 175 mm
The size of the medium hot plates:
250 * 250 mm, 250 * 500 mm, 300 * 300 mm, 115 * 600 mm
And the size of the giant heating plates for the lab:
400 * 600 mm, 600 * 600 mm
The huge plates have high power consumption and require three-phase power supply.
The plates can be ordered with separate temperature control.
And plates with dimensions can be produced on demand.
- Temperature control
-An analog thermostat when temperature accuracy is not important.
-Digital temperature control will allow precise temperature control of a single degree, option to set heating rate, option for timer, option for computer communication.
External temperature tracker: There is a difference between the temperature of the plates and the temperature of the media or the part that rests on the plates.Because the temperature sensor is inside the plates and measures the temperature of the plates, the temperature of the liquid or part placed on it is lower than the temperature of the plates.
- Safety controller for overheating protection - Another independent control circuit that will switch off the heating in the event of a fault in the main control circuit.Add safety controller in long processes at nights and weekends when plate works unattended.
-Temperature programmer -Determining a temperature profile -Program or multiple programs with several segments of different temperature.
The temperature uniformity of the plate can be checked with a temperature meter and a surface tracker A surface tracker makes good contact with the measured area because it is thin, wide and springy and allows the user to check the temperature at different points of the plate to find out its temperature uniformity.As you move away from the edges of the hot plate towards the inside of the hot plate, the temperature uniformity improves.If you want to check the temperature uniformity over time at several points on the hot plate, use a data logger of several measurement channels.
Special Hot Plates for the Laboratory
If working with aggressive chemicals and depending on the use made of the plate, the plate can be coated with Teflon or anodized. , Copper Hot plates can be produced, Hot plates can be produced with water cooling or cooling of liquid nitrogen.
Precautions When Working with a Hotplate
Keep away from flammable materials - because the braces are exposed, the workers should be warned and it is even advisable to hang a careful sign. It is advisable to work with gloves designed to work in the heat and with forceps.