A demagnetizer is a device that uses electromagnetic fields to reduce or remove the residual magnetic field from objects such as permanent magnets, tools, electrical components, and other equipment. Demagnetizers are designed to reduce the build-up of static electricity in sensitive equipment and eliminate potential errors due to misalignment caused by interfering magnetic fields. This type of tool is particularly useful in industries such as automotive, electronics, and machinery manufacturing where precision machinery is used regularly.
A typical demagnetizer contains an alternating current (AC) transformer that produces a reversing electromagnetic field through a loop connection to the object. The reversing field helps to reverse the magnetic polarization—the opposite poles of the magnet—and two capacitor-resistor networks that generate a higher frequency signal that causes the magnetic field to rapidly decay. As the static build-up of the objects magnetic field decreases, the sensitive precision equipment’s performance improves.
Demagnetizers come in two primary forms: automated and manual. Automated demagnetizers are used mostly in factory settings and are typically triggered by sensors or digital inputs, such as a press button or contact sensor. Manual demagnetizers require users to manually move the demagnetizer around the object to reduce and remove its residual magnetic field. In either case, it is important that users follow the manufacturer’s instructions for proper operation and safety. Additionally, the use of personal protective equipment, such as gloves and eye protection, is recommended when handling demagnetized objects.