Hi,
1, confectionery products, This is an international forum, and we may not know the name very well.
Generally speaking, this should be a product that is easy to detect, and there is usually no product effect.
Of course, I can't fully confirm. if possible, you can post a few photos of the product.
2, Do you have a picture of the machine? Because I want to know the specific situation of the machine.
3, The sensitivity of the machine is not directly related to the test rod size.
Even for test rods of the same size, the sensitivity may vary greatly.
So further, I want to know what signal value is your product and test rod respectively?
4, because even for test rods of the same size, the sensitivity may vary greatly.
Therefore, you need to ask local professional engineers to increase the sensitivity of MD as much as possible.
This of course includes the lowest possible interference including product effects.
5, If your MD hole size is too large, then you may also need to change to a smaller size.
So I also want to see your machine photos.
6, Do you have photos of metal contaminants complained by customers?
Of course, this is not important. MD has 2 most important aspects:
6.1, The highest possible sensitivity. ( Of course stability must be considered.)
6.2, An almost absolutely reliable rejection system. ( This is also actually a complicated topic. )
So, this is not a simple question.
If you can directly respond to the above questions, I will continue to answer / help.
Thanks.