gradiometer

gra di om e ter |ˌgrādēˈämitər ɡreɪdiˈɑːmɪtər | ▶noun a surveying instrument used for setting out or measuring the gradient of a slope. • Physics an instrument for measuring the gradient of an energy field, esp. the horizontal gradient of the earth's gravitational or magnetic field.

gradiometer

gradiometer |ˌgreɪdɪˈɒmɪtə | ▶noun a surveying instrument used for setting out or measuring the gradient of a slope. • Physics an instrument for measuring the gradient of an energy field, especially the horizontal gradient of the earth's gravitational or magnetic field.