Before revision: "Dip meter" can also refer to an influential early commercial expert system called Dipmeter Advisor; or may refer to an instrument that measures the "dip angle " of the planet 's magnetic field, the field line angle in a vertical plane.
After revision: "Dip meter" can also refer to an influential early commercial expert system called Dipmeter Advisor; or may refer to an instrument that measures the magnetic dip angle of Earth 's magnetic field, the field line angle in a vertical plane.