What device is used to measure the magnetization and strength of a magnet?
The strength of permanent magnets is determined by a Teslamer or Gaussmeter. Using these devices, you can determine the magnetic induction of a neodymium magnet and determine the grade of the material (N35, N38, N40, etc.)
What happens if you saw or drill a neodymium magnet?
You will spoil the magnet and be injured. The fact is that neodymium magnets are very fragile. External influences on the magnet outside the factory conditions lead to its demagnetization. Do not take these actions.
What if I need a magnet of a custom shape and size?
It’s that simple! Send to e-mail email@example.com the following parameters of your future magnet:
size and shape (drawing or drawing)
magnetic field direction
magnet coating material (nickel, zinc)
other special requirements and wishes
Can a neodymium magnet demagnetize?
Maybe, but only if the operating rules are not followed. Namely:
when the magnet heats up over 80 degrees Celsius
under the influence of radiation
when using a magnet in high humidity conditions
Tell us about the main properties of your neodymium magnets.
huge selection of sizes and shapes
Is it possible to cut a magnet with a hacksaw for metal?
In theory, yes, but it will take you much longer, plus it will be more difficult for you to get rid of the “sawdust” that will firmly stick to the resulting pieces.
In this regard, the question arises. how to cut a magnet?
To begin with, we note that you will not be able to get two pieces of a magnet, each of which will have only one pole (if suddenly this is the purpose of your research). the phenomenon of a magnetic monopole, although predicted by physicists with iron certainty, has not yet been observed.
If we are talking about a flexible magnet (like on a refrigerator), then there should be no problem with cutting, since here you can handle with ordinary scissors.
If our task is to cut a “real” magnet, which contains iron and graphite, then we will have to work a little. In order for the cutting operation to be as efficient as possible, we need: a vise, an angle grinder, a diamond-coated disc (such discs are used for cutting extremely hard metals) and water. It is recommended to use a respirator during work, as fine hazardous dust appears when cutting the magnet of the angle grinder.
Before starting work, try to file a magnet from one of the edges. some types of magnets fundamentally cannot be processed (they just crumble).
Next, we act like this:
- Using a nail and a ruler, mark the cut line on the magnet.
- Fix the magnet in a vise (using spacers in the form of soft metal plates at the ends. so as not to damage the surface).
- Cutting is done along the marked mowing line with minimal effort. Cutting will take a long time, since it is not recommended to rush: in case of sudden movements or excessive pressure, the cut will be torn, and the magnet itself may burst.
- Periodically, the cutting must be stopped to cool the magnet. In case of overheating, it can lose its magnetic properties, so a container of water should always be ready.
- At the end of the cut, you will receive two magnets. It is recommended to wipe their edges with a damp cloth to remove the magnetized dust left after cutting.
What is a neodymium magnet
This product is made of an alloy of neodymium with iron and with the addition of a small amount of boron. Neodymium is one of the rare earth metals of the lanthanide group, it serves as the main link, and iron acts as a link in the alloy.
In terms of power, neodymium magnets outweigh the usual ferrite ones by 18-20 times. In practice, this property is manifested in the fact that when two neodymium products are connected together, they cannot be disconnected without additional devices. Regular magnets can be detached from each other with a slight amount of force.
Neodymium devices first began to appear in Japan and the United States, developed in the early 80s by General Motors, which collaborated with Sumitomo Special Metals. They are used in almost all areas of industry: in the production of medical or technical equipment, security systems, household appliances, electronics.
These powerful devices are indispensable in mechanical engineering, in mineral processing, in robotics, for performing scientific experiments, various experiments. At the household level, they are often used by owners of private or commercial housing to stop all types of metering devices.
What electricity meters can be stopped by a magnet
Neodymium is able to slow down the counter mechanism many times over, which reduces the number of kilowatts on the display. Currently, several types of accounting devices are used. Only devices with transformer coils are stopped with a neodymium magnet for an electricity meter.
The names of these old counters begin with the letters CO (with some exceptions), for example, SO-I496, SO-193, SO-EE6705. To stop them, permanent magnets or foreign objects are used that can act on the disk device.
Another type. hybrid meters. make up about 80% of all household and industrial electricity meters. They are equipped with:
- digital screens;
- mechanical calculating devices;
- measuring unit (induction or electrical).
They practically do not stop with magnets. The brands of hybrid devices common in our country: Mercury 201 and 203, Energomera TsE-6807, Neva-103, SOLO, etc.
Fully electronic meters are distinguished by increased readings clarity, the ability to set several tariffs, and remotely take readings. They are equipped with:
- LCD display;
- measuring sensor;
- extensive set of functions.
The magnet is useless for them. They are stopped only with the use of a pulse device, for example, when you need to deceive the electricity meters standing in apartment buildings or on poles.
If the electronic meters are pre-configured, remote controls are also used to stop them. The stopping procedure using the remote control lasts 1-2 seconds and is invisible to outsiders.
How to choose a magnet to stop an electric meter
Consider what kind of magnet is needed to stop the electricity meter. It is recommended to ensure that its parameters and power correspond to the model and functionality of the meter. For example, for older models, thin washers are suitable, for later models. overall “tablets”.
The size of the produced magnets is from 1 mm to 12 centimeters. To stop metering devices, products with a size of 50-70 x 20-50 mm and an adhesion force of 85-200 kg are usually used. If you install a magnet that is too large, the counters quickly fail. It is necessary to take into account the optimal ratio of the width and height of the product, it should be 20: 1.
You can find out which magnet is suitable for a particular type of measuring device from the following table:
|Micron SEO. 1.15, 1.15D||50 x 20|
|SKAT 101M-1-3 Sh2 P1|
|Meridian LTE||45 x 30|
|Micron PSCH-3A||50 x 30|
|NIK 2102 02, 2102 02 M2V, 2102 04, 2301 AK1, 2301 AP3|
|SKAT 301M-1-4 Sh P2||60 x 30|
|CA4-199||70 x 40 and 70 x 50|
|SO-2, SO-505, SO-I446, SO-I449, SO-E449 1M, SO-EA05M1|
Properties and principle of operation
Neodymium magnets have the following properties:
- Increased resistance to demagnetization.
- Stability: retain their characteristics for decades. For 10 years of operation, they lose no more than 1% of properties.
- High gravity and traction power, optimal strength-to-value ratio.
- Reduced corrosion resistance.
- Low resistance to temperature rise. Depending on the brand of the product, the maximum temperature is 80-250 ° C.
With proper storage and use, the service life is at least 30 years, but this is a rather fragile material and, if handled incorrectly, quickly loses its properties.
A neodymium magnet on an electric meter is able to influence the density of the magnetic field, its induction is enough to slow down the operation of the device by 7-9 times. Accordingly, electricity costs are reduced in the same proportion.
The table below shows the magnetic characteristics of various neodymium alloys, which are laid down at the manufacturing stage and remain unchanged throughout their service life:
Classification of neodymium magnets
These magnets (designated as NIB or NdFeB) differ in a variety of sizes and shapes: they are available in the form of cones, discs, squares, quadrangles, rings, rods, balls, with or without a hole. Nickel coated top to protect from scratches or damage.
Subdivided into classes according to:
- the amount of energy;
- spread of operating temperature;
- the magnitude of the adhesion force;
This table shows the classification of magnets based on operating temperatures:
|N (Normal)||80 С (normal temperature)|
|M (Medium)||up to 100 С (increased)|
|H (High)||up to 120 С (high)|
|SH (Super High)||up to 150 C|
|UH (Ultra High)||up to 180 C|
|EH (Extra High)||up to 200 C|
Numerical characters (40UH, 38SH, 33M, N30) represent energy (measured in kJ / m 3). It is a measure of power or “breakout force”. Indicates the force required to lift the device from the surface. The larger the number, the more power.
Attention! The “pull-off force” is largely dependent on the mass and size of the magnet. For example, a device with an area of 2520 mm 2 is much easier to detach from metal than a device with a size of 405 mm 2.
The classification is also made by the amount of magnetic moment per unit volume:
- N28EH. N35EH.
According to the direction of the magnetic field, neodymium products are divided into axial, where the field is directed along the thickness, diametrical (along the diameter) and radial (towards the center of the radius).
Does a neodymium magnet work for a modern electricity meter
The neodymium magnet is considered the most powerful of all types known to science. It is widely used in all branches of industry, in scientific research, in invention.
How is a 6″ neodymium magnet delivered?
Quite often it is used as a magnet for an electricity meter. In terms of power and other properties, it is noticeably superior to the usual black ferrite ones, which cannot be stopped by metering devices.
How much do neodymium magnets cost for electricity meters
The first neodymium magnets put on the market were quite expensive. Neodymium is a rare element, and manufacturers and developers compete with each other.
Now the price has decreased slightly, but it cannot be called low: the cost is from 1000 rubles. for products of class 1 up to 7,000 rubles. for class 5 products.
Approximate cost depending on size (in mm):
- 60 x 30. 1,700 rubles.
- 55 x 25. 1200 rubles.
- 70 x 50. 3 800 rubles.
- 50 x 30. 1 100 rubles.
- 50 x 20. 1 100 rubles.
- 45 x 30. 1,000 rubles.