metal detector distinguish between metals with the same type

Hi every body
I want to know how can I change my VLF metal detector to distinguish between two metal
with the same type at nearby places?

thanks a lot

check this out. this may be helpful.

Good luck

What type of VLF (Very Low Frequency) metal detector are you using?
Metal detectors can distinguish metal objects from each other based on the ratio of their inductance to their resistivity and this ratio gives rise to a predictable delay in the receive signal at a given frequency. In order to do so you need to provides on the detector side some individually programmable notches.
Using "Notch Discrimination" a metal detector can be set to show the identification of the target for different targets within a certain range, but I’m afraid in the case of two identical metal objects placed nearby, you need to have some sort of graphic display showing a numerical value on the horizontal axis and the strength of the signal on the vertical axis, as the loop is moved above them may distinguish the objects.