Metal Detector Advice

[Wilder1988]

I am trying to create a Metal Detecor Strip... This would consist of 24 inches wide and around 2 inches long. Preferably Battery operated. This strip would be strong enough to detect a small peice of metal that would be maybe a quarter of an inch by a quarter of an inch.... The first thing that I need to know is if this design is possible based off of what my requirements are..

Or

Would it be less expensive to use RFID technology? I understand how RFID chips work, and those can be farely inexpensive... but I do not know how much the strip would cost that could detect RFID chips..

CLARIFICATION: MY goal is to create a sensor 24" by 2" that would go along a door way, that would detect a small chip (whether the chip is made of metal or an RFID chip)..

Any suggestions and advice would be amazing. Thanks!

[PinkertonD]

Hi and welcome,

Within reason and depending on other metallic objects within the vicinity, a metal detector can by pretty large. The actual detector part of the equipment is generally a simple wire loop. Often multiple loops of a single wire, so you could make a 24" x 2" wooden former and wind your detector coil and then encapsulate it in epoxy etc.

Do some research on metal detector kits and I am sure you will find what you are looking for. There is quite a bit involved if the parts to be detected are moving as opposed to static. Also the inductance of the loop will need to be tuned for and with the circuitry involved. Another approach might be an array of Hall-effect sensors.

I cannot imagine how you would use RFID for detecting small pieces of metal.

[Wilder1988]

@Pinkerton

I need to edit my original post, I ment using RFID as the item to be detected, would it be cheaper to make a sensor that senses RFID chips instead of making a metal detector to detect metal chips... Does that make sense??
I appreciate the reply anything helps at this point!

To help clarify what I would be using this for.. My goal is to create a sensor strip 24" x 2" that could detect a small chip... My first instinct was a metal detector style of a set up... or using the RFID technology...

Also the strip would be along a door, so anything passing into the door would be detected...

[RWOLFEJR]

Near as I can tell you are wanting to detect RFID chips? Not read the chips information... Just detect their presence?

Or do you want to detect metallic things regardless of what they are?

I'm almost certain I won't be of any help in answering your question, but I'm thinking your question could use clarification to any who might be able to help you with this. I only know enough about RFID technology to be both amazed and terrified by it.