Generally, a metal detector does not react to glass. There are situations where a metal detector will react to metal that is in close proximity to the glass and often bottles will have a metal cap or ink in inkwells. A metal detector cannot detect it.
Best metal detectorsEditors pick: Garrett AT Pro Metal Detector. Courtesy of Amazon. Best for low prices: Garrett ACE 400 Metal Detector. Courtesy of Amazon. Best all-terrain detector: Minelab CTX 3030. Best for underwater: Minelab Excalibur II. Best for finding gold: Nokta Gold Kruzer Waterproof Metal Detector.12 Jan 2021
Is there such a thing as a glass detector?
It is totally possible to detect all sorts of metals through glass. Yet, you need to take into consideration few things … So, it you recognize metals like copper, lead or even gold with specific tones … through glass these tones wont sound the same!
Most metal detectors can detect objects about 4-8ʺ (10 - 20 cm) deep. In ideal conditions, a mid-range metal detector can reach 12-18ʺ (30-45 cm) underground. Some specialized detectors can go as deep as 65 (20 m).