Hall effect or proximity sensor?

What is the difference between a Hall effect transducer and a proximity sensor? It looks like one is general term and the other is a specific type.

I have a recipe for an anchor chain counter that calls for imbedding a magnet in the chain wheel and sensing it with a hall effect transducer with sourcing output. I have a selection of Omron proximity sensors with both sourcing and sinking outputs that can detect bolt heads and gear teeth and don't need the magnet. Can I safely assume that they can be substituted?

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Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
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Glenn Ashmore
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A hall effect sensor responds to the external magnetic field in some way. It may be a linear response to the field passing through it, or it may include a threshold sensor that switches a transistor on and off as the field passes through distinct values. If you bias a hall effect sensor with a permanent magnet, the combination may be made to sense the presence of a ferromagnetic object near by.

A proximity sensor is a complete system for sensing the presence of a particular kind of material. It may be based on an AC magnetic field generated by an internal oscillator, and electric field generated by an internal oscillator or the variation in the DC field generated by an internal magnet. Each type serves best in particular circumstances and poorly in others. You really need to read up on how the various types work and what their specifications are before designing them into a system. The key word you need to add to any other search parameters is [tutorial].

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John Popelish
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John Popelish

Some of you guys are very helpful but a few are down right condecending. The title of this group is sci.electronics.BASIC.

I have been working with proximity sensors for some time and have completed several very successful projects. I am familliar with their detection capabilities and the signals they output. What I wanted to know was if hall effect transducers had some intrinsic advantage. I gather from your response that they do not.

Thanks for that anyway.

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Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
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Glenn Ashmore

Hey! It took me a long time for me to figure out to add that word when I was looking for an explanation of how something worked, instead of where to buy something.

They are good for some applications, but they are not the most common industrial sensors. Part of the reason for that may be that good, reliable integrated hall devices have not been available until recently. One of their short comings is that the permanent magnet used to bias them tends to make them accumulate bits of iron. The AC field devices do not attract such debris.

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John Popelish
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John Popelish

On Thu, 24 Feb 2005 00:06:27 -0500 in sci.electronics.basics, John Popelish wrote msg :

re:[tutorial]

Capitalism, the bane of Google. :-) IMO, I think your idea is good.

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Al Brennan
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Kitchen Man

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