isolead
/ˈaɪsəˌlɛd/
noun
- A line on a map or chart connecting points of equal electrical potential or equal lead (in surveying or navigation).
- The navigation chart included an isolead to help sailors find areas of consistent depth.
- On the electrical map, each isolead represents a constant voltage level.
- The surveyor drew an isolead to mark all locations with the same magnetic reading.