Conditioners and Demagnetizers
A conditioner is a device that is used to selectively adjust the magnetic strength of a part to a specified value. In the past, conditioners have been used to simply “knock-down” the magnetic field of low-coercivity magnet parts (such as alnico and ferrite) until a certain field level was achieved. The resulting part was slightly weaker, but had a field strength that was repeatable.
For modern magnets, a conditioner is used to adjust the overall performance of a complete device based on any measurable parameter (not just the magnetic field strength), in order to make the device more accurate. The magnet in this device is knocked-down until the measurable parameter reaches the desired level or is within an acceptable tolerance.
A typical example of the conditioning process involves Form B reed relays. These devices contain a pair of switch contacts surrounded by a small coil of wire with a small biasing magnet next to it. When no voltage is applied to the coil, the magnet pulls the two contacts together. As voltage is applied to the coil, the field of the biasing magnet is opposed. Once the voltage reaches the proper level, the effect of the magnet is cancelled out and the contacts are able to pull apart. In spite of errors caused by the magnet strength, positioning, number of turns in the coil, and the resistance of the wire, the device can be conditioned so that the contacts open at the same specified voltage for each part.
Oersted Technology conditioners and demagnetizers operate under computer control and are designed to process a particular number of parts within a time period selected by the customer. These machines are designed specifically for the customer’s application and can be equipped with automatic part loading, go/no-go indicators, and other options.