Who is credited with inventing the first practical metal detector?

Who is credited with inventing the first practical metal detector?

پہلا عملی میٹل ڈیٹیکٹر ایجاد کرنے کا سہرا کس کو جاتا ہے؟
Explanation

 Alexander Graham Bell is credited with inventing the first practical metal detector

He developed it in 1881