6 replies to this topic

[alex gatambiye]

Hi,

I am facing an issue with our method of validating our metal detector. I pass the probes through the detector in a plastic, then pick it up in the reject bin. This is for me to be able to tie it and pick it in case the detector fails to pick it. The audit is requesting to find an alternative method that does not involve the plastic. Could you kindly advise what else may I use?

[SQFconsultant]

Without the plastic.

 

But the question is - what was the reason you were using plastic to begin with?

[Scampi]

You should be sending them IN your actual product in order to validate that the MD works for each product you make, not that it can detect just the probe

[nwilson]

You should be looking into why your parameters are not set right for the products your running if you test rod/card/probe is rejected by itself. I would be contacting the metal detector manufacturer or a licensed technician to review and make sure everything is set up correctly.  Agree with other on leave the plastic out of this situation it just another variable to deal with.  

[G M]

I'm still a little confused about _why_ you're putting it in plastic? I'm interpreting this as placing the verification seed inside a plastic bag because the line is messy, or the seeded device is susceptible to wear if it is cleaned repeatedly.  Or are you putting it inside some plastic object that is simply easier to pick up quickly if the reject mechanism fails?  

 

We stopped using the laminated card type verifications seeds because of durability -- they would delaminate and pose FM problems themselves after repeated washing.  We're using more durable seeds encased in solid plastic now.

https://www.testrods...-fe-nfe-ss-316/

 

 

While it is preferable or best practice to put your test seed inside your product as others mention, if your product is invisible to the detector it makes little difference.

[siskos]

The way I use is placing the metal samples in the products and pass them in the metal detector. I am repeating the procedure placing the samples in different higths and orientation to check if the detection is homogenous in the detection area.

 

I have noticed that diferences in atmosphere moisture static electricity loads etc can affect the sencitivy so is crucial to check it very well 

[Planck]

Hi,

I am facing an issue with our method of validating our metal detector. I pass the probes through the detector in a plastic, then pick it up in the reject bin. This is for me to be able to tie it and pick it in case the detector fails to pick it. The audit is requesting to find an alternative method that does not involve the plastic. Could you kindly advise what else may I use?

"This is for me to be able to tie it and pick it in case the detector fails to pick it."

You mean, you tie your test wand with a thin piece of string? And then your hand holds the end of the string for the verification operation?

 

Am I understanding this correctly? Or could you take a photo or video?

 

If I understand you correctly, and I am defaulting to your MD being a conveyor belt machine, then there are two very important details involved here:

1, Thin string traction, which can cause your test wand to be out of sync with the product, i.e., the speed is different from the speed at which the product passes through.

The speed parameter is a key parameter in determining the sensitivity of the MD and must be correct.

 

2, Since the speeds are different, then you can't actually verify the rejector correctly.

Accurate rejection is equally important, and this is often ignored by users.

 

3, you said,,if detector fails...??

If you use a test wand to verify your MD, generally a failure shouldn't happen.

I think at a minimum, you should make sure that you test 1000 times without failures occurring. Or at most 1 or 2 occurrences.

If it's more, say more than 10 times, then it's almost completely unacceptable.

 

We are actually a technical service provider for metal detectors, we mainly provide technical services for LOMA equipment and the basic standard for our direct customers is 10,000 times. The highest we've recorded is 260,000 times, and it could actually be higher, but it's reliable enough that we don't want to keep following up on it.

 

Note that this actually represents superior sensitivity and stability, so if it exceeds 1% it is almost absolutely unacceptable.

 

Any MD technical questions can be directed to us: support@devodt.com