Reed switches in Ferrous part detection

For a cost effective solution to be used in heave machine automation where magnets cannot be used due to the sheer bulk of ferro-magnetic parts, Reed Switch based ferro-magnetic detection sensors are useful.
Ferrous part detection sensors are built by positioning two weak magnets near the seals of reed switches. The two magnets are by themselves not strong enough to transfer the magnetic flux lines between them and close the reed switch. But if this system is brought near a ferrous part, the flux lines travel through the ferrous part and enlarge the two smaller field into one big field which then close the reed switch.
As the current carrying capacity is not affected by this sort of construction with multiple magnets, various sizes of reed switches capable of switching different levels of power are available. Ferrous detection sensors can be used in a wide variety of applications in pick and place units, for sensing steel doors of factories and cargo etc.
Application Classification
Applications are classified as Position Sensing, Pulse Counting, Electromagnetic or Relay, Temperature Sensing or Magnet Biasing types. This application is classified as follows and the link gives more information on best practices to help select the most suitable AT band and matching magnet.
Magnet Biasing Type
![]() | Some special field applications, for the sake of circuit logic, or security concerns, require...Continue reading |
Recommended Products
The Reed Switches and Sensors used in such applications need to be robust, durable and efficient in meeting a high life expectancy. Our engineers work hard in life testing our products under various conditions, and our intention is to ensure end product durability and life. Although we wouldn’t want to restrict any of our products for use in only certain applications, the recommended products for use in this application are listed below.
FM-328, Standard Ferro-magnetic Metal Detection Sensor
![]() | Does not require power for operation, Normally Open contact form, Detect any Ferro-magnetic material,...Continue reading |
FM-324, Miniature Ferro-magnetic Metal Detection Sensor
![]() | This miniature Ferrous Metal detection sensor can detect any ferrous metal with a distance...Continue reading |
MC-1425 Miniature Close-differential Reed Switch
![]() | The MC-1425 is a 14.0 mm glass, Form A type Miniature reed switch with...Continue reading |