Definition and function of magnetic stirrer – In the laboratory, usually a researcher often performs various practicums. Researchers often mix chemical solutions in a beaker for analysis. The substances to be dissolved must be mixed until homogeneous or completely mixed. To get this perfection, a researcher needs a stirrer called a magnetic stirrer .
Before using this tool, a researcher needs to understand the meaning and function of the magnetic stirrer in order to use this tool optimally. This tool is used by researchers because to dissolve chemical liquids researchers must be able to stir constantly. This is not possible if stirred manually. In this article the author will explain the meaning and function of the magnetic stirrer in a clear and easy to understand manner.
Definition and Function of Magnetic Stirrer
What is a magnetic stirrer ? Magnetic stirrer is a laboratory instrument used to stir a solution by heating using a magnetic rod inserted into the solution container. Mixing liquids or solutions that have low viscosity often uses a magnetic stirrer to make it homogeneous.
As just discussed, the magnetic stirrer stirring process is assisted by a magnetic bar or commonly known as a “stir bar”.
A magnetic stirrer is a stirrer that uses a magnetic field to move a stir bar or a stir bar that is placed in a liquid solution so that it will help mix the solution homogeneously. Besides being useful for stirring, a magnetic stirrer can also heat a liquid solution magnetically and mechanically.
A magnetic stirrer can also be referred to as a magnetic mixer which is a laboratory tool that uses a magnetic field to move bars or flea . This magnetic field causes the bars that are placed in the liquid to rotate according to the speed set by the user of this tool.
Magnetic stirrer is also usually combined with a hotplate in order to be able to regulate the temperature of the liquid at the time of stirring.
What is a stir bar?
A stir bar is a bar magnet with a ring raised in the middle to rotate around the tool. Like the picture above, generally the stir bar has a shape like white pilus. The length also varies from mm to cm. This stir bar or stir bar is simple in shape, so it is easy to clean and disinfect. Oh yes, the stir bar is magnetic or also known as a magneton. This part is very important for the stirring in the liquid with the rotation process.
A. Magnetic Stirrer Function
There are several functions of the magnetic stirrer in the testing laboratory, including the following:
1. Has incredible speed
The speed possessed by this magnetic stirrer tool exceeds the speed of the human hand in stirring a solution. If this solution is stirred by human hands, it will take a long time so that this will make it difficult for researchers to work. This of course will make the performance of the researcher decrease.
In addition, the use of a magnetic stirrer can also be very fast which will make the liquid solution mix faster. So, researchers can analyze the liquid solution. If the researcher does not use this tool, the researcher will need a long time to stir and analyze a practicum.
2. Stirring stably
This magnetic stirrer can stir the liquid solution stably and quickly. This speed can be set by the researcher when using this tool. Bars or flea placed in a liquid can rotate stably and quickly so that it can stir the liquid solution completely or homogeneously.
The homogeneity of a liquid solution will clearly affect the results of the quality of the analysis of researchers in examining a liquid solution. If the researcher cannot stir stably, the results he will get will also be less accurate. This can be an untruth in doing the practicum.
3. Stirring constantly
The use of a magnetic stirrer can facilitate the work of researchers because this tool can stir constantly. Where, if the researcher stirs manually it will be difficult to get a constant mix. Because the energy of each researcher will be different, the results of the stirring speed will also be different and cannot be constant.
If the researcher does not use a magnetic mixer in stirring the liquid solution. The liquid will not be mixed perfectly or there will even be a clotted solution so that this will affect the quality of the research carried out because constant stirring can only be obtained by using a magnetic stirrer.
B. Advantages of Using a Magnetic Stirrer
The small size makes the bars on the magnetic stirrer widely used in practice. This selection is based on the stability and stability of the magnetic stirrer rather than manual stirring. In addition, it is more efficient and has no externally movable parts to break or wear.
The small size makes the bars or fael much easier to clean and sterilize than other devices. This tool does not require lubricating oil which can contaminate the beaker or liquid solution. In addition, this tool can also be used for closed vessels because the magnetic stirrer does not require complicated rotary seals compared to other laboratory equipment.
C. Working Principle of Magnetic Strrier
The working principle of a magnetic stirrer is by utilizing a magnetic field or a stationary electromagnetic which becomes a motor in moving a bar or a substance in stirring a liquid solution. This magnetic field will make this magnetic stirrer able to stir liquids quickly, steadily and constantly.
In optimizing the working principle of the magnetic stirrer. Choose this tool that fits the beaker or container to be used. If the selection is not right, this will certainly make this tool unable to work optimally. And the results that will be obtained by researchers will not be optimal. For more details, here are the principles and how the magnetic stirrer works:
1. Magnetic Principle
- Magnetic stirrer is used to mix all kinds of liquids
- The stirring produced by this tool is using a magnetic field
- The size of the magnetic stirrer speed can be adjusted according to the needs of researchers or users
- Using this stirrer can speed up homogenization
2. How Magnetic Strirrer Works
- Prepare a container that already contains the liquid solution
- Place the container on the hotplate
- Turn on the hotplate by connecting to the mains
- set the hotplate temperature by setting the temperature setting button
- Put the magnetic stick into a container in which there is a solution
- Then, adjust the magnetic stirrer speed by pressing the stirrer magnetic adjustment button clockwise.
- If, the stirring speed is too high, adjust it again by turning the magnetic adjustment knob of the stirrer counterclockwise
- Stir until the liquid solution becomes homogeneous
- When finished, remove the magnetic stirrer from the liquid solution container
- Turn off the hotplate by disconnecting from the mains
- Take the container with hot hands
D. How to Care for Magnetic Stirrer
Maintenance on the magnetic stirrer tool is carried out to prevent damage and prolong the service life of the tool. There are several efforts you can do to treat magnetic stirrer tools, including:
- It is recommended that you store the instrument on a flat, dry and clean surface.
- Do not connect the power supply until the base surface has dried.
- We recommend that you do not just spray the cleaning solution into the instrument to prevent corrosive damage to the instrument.
- During mixing, when the stir bar is not stirring, reduce speed or disconnect power to check.
- Medium speed operation can continue to work for 8 hours, high speed operation can continue to work for four hours, this is done to prevent severe vibration during operation.
- To clean it, you can use some cleaning solutions such as aopropyl alcohol and water containing tension.
- The instrument housing must be properly grounded to avoid accidents.
- Routinely calibrate, especially at its temperature.
Magnetic Stirrer Calibration
Calibrating is one of the efforts to maintain the magnetic stirrer. This is useful to ensure the accuracy of the tool. If the magnetic stirrer is used frequently, the calibration is carried out every 3 months. Meanwhile, if it is rarely used, the calibration is once a year. The calibration of this tool will focus on the temperature because the heat energy produced greatly affects the stirring results. Then, how do you calibrate the magnetic stirrer?
- Begin calibration by using a thermometer calibrated to 300°C.
- Place the beaker or flask containing the sample in the center of the heating plate.
- Press the ON button to turn on the appliance. Operate the magnetic stirrer without using a magnetic stirrer or stir bar
- Set the temperature by turning the temperature control knob.
- Dip a calibrated thermometer into one side of the beaker.
- Record the control panel temperature display and the temperature of the thermometer being calibrated.
- Repeat the procedure at a different temperature. And note the temperature.
That’s the function of the magnetic stirrer that you can know now. Hopefully the readers will understand more about this laboratory tool. You can also look for other references about the magnetic stirrer function on other sites to add more insight.
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