A sensor arrangement for an injection device to determine an axial position of at least one device component (12; 212; 30) of the injection device inside a housing of the injection device, the sensor arrangement comprising: - an elongated member (12; 212) located inside the housing, extending in an axial direction (1, 2) and having at least a first section (12a; 212a) and a second section (12b, 12c, 12d; 212b, 212c, 212d) of different magnetization and being separated in axial direction (1, 2), - at least one magnetic sensor element (22.1, 22.2, 22.3) attached to the housing to detect the axial position of at least one of the first and second sections (12a, 12b, 12c, 12d; 212a, 212b, 212c, 212d), - a second device component mechanically engaged with the elongated member (12; 212) and axially displaceable along the elongated member (12; 212), characterized in that the second device component is configured to attenuate or to amplify the magnetic field of the differently magnetized sections (12a, 12b, 12c, 12d; 212a, 212b, 212c, 212d) of the elongated member (12; 212), and wherein the second device component is threadedly engaged with the elongated member (12; 212) and is rotatably fixed to the housing but is slidably displaceable relative to the housing, or the second device component is threadedly engaged with the housing and is rotatably fixed to the elongated member (12; 212) but is slidably displaceable relative to the elongated member (12; 212). - an elongated member (12; 212) located inside the housing, extending in an axial direction (1, 2) and having at least a first section (12a; 212a) and a second section (12b, 12c, 12d; 212b, 212c, 212d) of different magnetization and being separated in axial direction (1, 2), - at least one magnetic sensor element (22.1, 22.2, 22.3) attached to the housing to detect the axial position of at least one of the first and second sections (12a, 12b, 12c, 12d; 212a, 212b, 212c, 212d), - a second device component mechanically engaged with the elongated member (12; 212) and axially displaceable along the elongated member (12; 212), characterized in that the second device component is configured to attenuate or to amplify the magnetic field of the differently magnetized sections (12a, 12b, 12c, 12d; 212a, 212b, 212c, 212d) of the elongated member (12; 212), and wherein the second device component is threadedly engaged with the elongated member (12; 212) and is rotatably fixed to the housing but is slidably displaceable relative to the housing, or the second device component is threadedly engaged with the housing and is rotatably fixed to the elongated member (12; 212) but is slidably displaceable relative to the elongated member (12; 212). in that the second device component is configured to attenuate or to amplify the magnetic field of the differently magnetized sections (12a, 12b, 12c, 12d; 212a, 212b, 212c, 212d) of the elongated member (12; 212), and wherein the second device component is threadedly engaged with the elongated member (12; 212) and is rotatably fixed to the housing but is slidably displaceable relative to the housing, or the second device component is threadedly engaged with the housing and is rotatably fixed to the elongated member (12; 212) but is slidably displaceable relative to the elongated member (12; 212).