Detector apparatus and detector system

A detector apparatus comprising a first magnetosensitive unit and a second magnetosensitive unit configured to detect a change in magnetic flux density that is caused by relative movement of a to-be-detected unit, wherein

• the first magnetosensitive unit includes (i) a first magnetic resistor element and a third magnetic resistor element that are arranged next to each other in a moving direction of the to-be-detected unit and (ii) a first resistor that is electrically connected to the first magnetic resistor element,
• the second magnetosensitive unit includes (I) a second magnetic resistor element and a fourth magnetic resistor element that are arranged next to each other in the moving direction of the to-be-detected unit and (II) a second resistor that is electrically connected to the fourth magnetic resistor element,
• the second magnetic resistor element is positioned between the first magnetic resistor element and the third magnetic resistor element in the moving direction,
• the third magnetic resistor element is positioned between the second magnetic resistor element and the fourth magnetic resistor element in the moving direction,
• the first resistor, the first magnetic resistor element and the third magnetic resistor element are electrically connected in series between a first potential and a second potential,
• the second magnetic resistor element, the fourth magnetic resistor element and the second resistor are electrically connected in series between the first potential and the second potential, and
• as for resistances for a same magnetic field, a relation of whether or not a resistance of the third magnetic resistor element is higher than a combined resistance of the first resistor and the first magnetic resistor element is the same as a relation of whether or not a resistance of the second magnetic resistor element is higher than a combined resistance of the second resistor and the fourth magnetic resistor element.