OT: metal detector help

The plant has a Goring Kerr tektamet metal detector before the seller shear machine. The Metal detector has started false tripping numerous times a day. This detector is roughly 14' wide.

I have done a internet search for manuals and came up with nothing but auctions sites.

The control panel has these adjustments

sens 0-10
phase 0-1000+
delay dial
reject dial
It also has a analog dial that show -10 to 10 but is not labeled what it represents.


I have turned the sens up and down with no change in the false tripping. The detector itself has been checked for any foreign objects.


thanks

It has been awhile since I worked on one of these.

Sensitivity is what you would think. Then higher it is the more non ferrous metal it can detect. We used a BB as a sample test.

Phase is where your highest zone of sensitivity is. Think of it as adjusting curtain up and down inside of the center of the machine.


Delay and Reject usually have to do with where your belt stops when it trips.

Not sure about the last item.

You have probably thought of this but I mention it because it bit me once.

Metal close to the detector has an effect.
One place I used to work had an operator who would push a metal table closer to the sensing head each night so he could put his "stuff" on it. Because of this tabel this shift had the highest false alarms until I figured out what was going on.

Those things are a real pain to work on.

Hope the info helps

thanks for the reply.

I have checked to make sure there is nothing near the detector that is not suppose to be. No metal seam tape on the sensing head( the usual problem).

The analog dial meter on the control board show -10 0 +10
If the meter is 0 and above it will not false trip. Once it goes in the negatives the metal detector will trip. I have adjusted the sens and phase through the whole range to try and find a place which will stay in the postives. The unit will work correctly for a few hours then act up again. The wire connections are tight.

please advise.

One thing that will drive us crazy on ours is ground loops, caused by deteriorated insulation from the apature to the frame it sits on. There could also be a build up of debris allowing the frame to contact the apature. These are our most common problems we run into with ours, well and of course the apature lifting from being washed with 140 degree water during washdown, but I don't think that is an issue in your plant. Gotta love sanitation!!

I have never worked with that brand, but two things we have found with our safelines:

-Cell phones near the sensor will set them off even if they are "turned off".

-Any vibration of the frame of the conveyor can cause this. One time we struggled for a week only to find that a stair platform several feet downstream had been pushed up against the conveyor frame and was rubbing against it when the conveyor ran.

Good Luck

OkiePC said:

-Cell phones near the sensor will set them off even if they are "turned off".

Click to expand...

Add CB radios and other plant communications radios to the list

OkiePC said:

-Any vibration of the frame of the conveyor can cause this. One time we struggled for a week only to find that a stair platform several feet downstream had been pushed up against the conveyor frame and was rubbing against it when the conveyor ran.

Good Luck

Click to expand...

Not sure if this is the same thing but any metal intermittently touching. I saw a demonstration once of how sensitive these things are. The person performing the test took about 30 feet of #12 THHN. Stripped the ends, made a loop around the sensor. No problems yet. Then he began to touch the ends, every time the ends touched or broke connection the sensor would trip.

wirepuller134 said:

One thing that will drive us crazy on ours is ground loops, caused by deteriorated insulation from the apature to the frame it sits on. There could also be a build up of debris allowing the frame to contact the apature. These are our most common problems we run into with ours, well and of course the apature lifting from being washed with 140 degree water during washdown, but I don't think that is an issue in your plant. Gotta love sanitation!!

Click to expand...

I have had trouble like when the frame itself made a loop,as well as loose jubilee clips. I have had inverters affect the metal detector - altering the carrier frequency helped.