A magnetograph is a device used for measuring the magnetic field of the earth or other celestial bodies. There are several synonyms for the word magnetograph, such as magnetometer, fluxgate magnetometer, and magnetic observatory. A magnetometer is a type of sensor used to measure the strength and direction of a magnetic field. A fluxgate magnetometer is a type of magnetometer that uses a pair of coils to detect changes in magnetic field strength. A magnetic observatory is a facility that studies the magnetic field of the earth or other celestial bodies. These synonyms are often used interchangeably to refer to devices and facilities that measure the magnetic field.