gradiometer
/ˌɡreɪdiˈɑːmɪtər/
noun
- A scientific instrument that measures differences in a physical field, such as gravity or magnetism, from one point to another.
- Geologists used a gradiometer to map underground structures without digging.
- A magnetic gradiometer can help find hidden metal objects like old pipes or coins.
- The archaeologist carried a gradiometer to detect buried walls and ditches.