Industrial Proximity Switches

[vignesh]

Figure shows a number of configurations of contact-type proximity switch being used in manufacturing automation.

These are small electrical switches which require physical contact and a small operating force to close the contacts. They are basically employed on conveyor systems to detect the presence of an item on the conveyor belt.

Magnet based Reed switches are used as proximity switches. When a magnet attached to an object brought close to the switch, the magnetic reeds attract to each other and close the switch contacts. A schematic is shown in below Figure.

Photo emitting devices such as Light emitting diodes (LEDs) and photosensitive devices such as photo diodes and photo transistors are used in combination to work as proximity sensing devices. Below Figure shows two typical arrangements of LEDs and photo diodes to detect the objects breaking the beam and reflecting light.

Figure- LED based proximity sensors

[Chris]

Any recommendations on good brands/types of magnetic proximity reed switch on a gas Bell Prover that ties into a timer to start counting when magnet mounted on prover comes in contact with switch as prover begins rising which starts the counter counting at first switch and then stops counting as the prover rises higher and comes across the next selected prox switches set up along the Bell prover rod which helps calculate the gas flow rate based on time (@ various distances among other things) .

Need information such as brand/type, 3 wire and recommendation on Timer that must be able to work with and be able to be wired up to with start and stop prox reed switches.

[vignesh]

I suggest Pepperl+Fuchs

Magnetic Field Sensors

[Chris]

Ok thanks.