Strong metal detector

[salvazero]

Hello,

 I would like to make a metal detector strong enough to detect a piece of stainless steel tape in the cable that we make.
We make electronic/electric cable, for example, sometimes this cable is bad and from the 50,000 feet we make, we have to cut it 3 times (we call that splices) because cable had a cosmetic defect so we cut that part out, now, we solder these splices to make one single cable so we can put the final plastic cover to make it one single piece without setting it up 3 times because of the splices.
I was thinking to make the detecting coil around a 2" or 3" PVC pipe so the cable/wire goes through and it will be easy to detect. It has to be strong enough to detect a 1/4” inch tape with 0.004” thickness that we want to put around these splices so they can be detected, make a beep and turn a red light, connect it to an 110 volt.
It needs to detect on 18-8 stainless steel tape, no iron, no copper, no aluminum, no silver, no gold, There are so many tutorials to make one online but I need this one to be strong and able to detect it.

Any help will be appreciated.

Thanks in advance

[Kleinstein]

Stainless steel near a thick copper conductor could be difficult to detect with a normal type of metal detector.  At least the search coils would have to be formed to work for short distance - as opposed to large distance with normal metal detectors. It really depends on the configuration, so where the extra piece of metal is. So a drawing of the approximate configuration would help.

If the extra metal is more to the outside, it might be easier to detect it as a capacitive change, not by magnetics as in normal metal detectors.

[Heszu]

That sounds perfectly doable.. With IB detector (Induction Balance). IB uses two coils TX and RX, and measures differences between coils.. When first setup with coil close to the cable, cable doesn't need to go through, balance as equal.. When cable goes By, at the exactly same distance, detector dont react. When the splice arrives the detector reacts on the difference in metal amount, which disturb the balance..
 Yes quite doable.


WBR
Heszu

[Brumby]

It would seem there is some hope for your cause - but it would really help if you could provide a drawing showing the normal construction of the cable (with dimensions) and what the difference is at the point you want to detect.