Calibration tool for calibrating a magnetic sensor

Calibration tool for calibrating a magnetic sensor, comprising

• a cuboid-shaped housing;
• and
• a predetermined number of two permanent magnets;
• wherein
• the two permanent magnets have a flat shape,
• the two permanent magnets have a same magnetization direction,
• the two permanent magnets are arranged along an axis and positioned in the housing, and
• the two permanent magnets provide in a working volume a homogeneous magnetic field that has a constant field intensity,
• and wherein
• the housing is configured to provide six alignment planes,
• the alignment planes extend either parallel or at an angle of 90° with respect to each other, and
• the housing has one or more holes allowing to position a magnetic sensor in the working volume.

Calibration tool for calibrating a magnetic sensor, comprising

• a cuboid-shaped housing;
• and
• a predetermined number of four permanent magnets, the four permanent magnets being a first permanent magnet, a second permanent magnet, a third permanent magnet and a fourth permanent magnet;
• wherein
• the four permanent magnets have a flat shape,
• the four permanent magnets are arranged along an axis and positioned in the housing,
• the first permanent magnet and the second permanent magnet form a first pair of permanent magnets,
• the third permanent magnet and the fourth permanent magnet are positioned outside the first pair of permanent magnets,
• the first permanent magnet and the second permanent magnet have a same, first magnetization direction in order to provide in a working volume a homogeneous magnetic field that has a constant field intensity,
• the third permanent magnet and the fourth permanent magnet have a same, second magnetization direction in order to provide in the working volume an additional homogeneous magnetic field that has a constant field intensity and points in a second direction,
• the first permanent magnet and the second permanent magnet are made of a same material having a first temperature coefficient of the magnetic field,
• the third permanent magnet and the fourth permanent magnet are made of a same material having a second temperature coefficient of the magnetic field which is different from the first temperature coefficient,
• the first magnetization direction and the second magnetization direction are opposite to each other if the first and second temperature coefficient have the same sign and are the same if the first and second temperature coefficient have different signs,
• the positions of the four permanent magnets along the axis are selected such that the temperature coefficient of the sum of the intensities of the magnetic field and the additional magnetic field in the working volume is zero,
• and wherein
• the housing is configured to provide six alignment planes,
• the alignment planes extend either parallel or at an angle of 90° with respect to each other, and
• the housing has one or more holes allowing to position a magnetic sensor (22) in the working volume.