  A calibration procedure for calibrations of triaxial magnetometers is
presented. The procedure uses a triaxial Helmholtz coil system and an
Overhauser scalar magnetometer and is performed in the Earth's field range. The
triaxial coils are first calibrated with the Overhauser magnetometer, and
subsequently, a triaxial magnetometer calibration is performed. As opposed to
other calibration approaches, neither Earth's field nulling system nor
movements of the magnetometer are needed. A real calibration test was carried
out-the extended calibration uncertainty was better than 430 ppm in sensitivity
and 0.06{\deg} in orthogonality.
