Another instrument, known as an imaging magnetograph, will provide two-dimensional magnetic field maps.
From the sciencedaily.com
Detection could build the case for constructing a measuring device called a coronal magnetograph for future deployment in space or on the ground.
From the sciencedaily.com
The flare was observed visually by Richard Christopher Carrington and the geomagnetic storm was observed with the recording magnetograph at Kew Gardens.
From the en.wikipedia.org
More examples
A scientific instrument that registers magnetic variations (especially variations of the earth's magnetic field)
A special telescope which analyzes the color and polarization of sunlight in order to measure the magnetic field of the Sun.
A picture of a magnetic field made by the use of iron powder under conditions that allow it to arrange itself into the pattern of the field.