Laboratory sample distribution system, comprising: - a number of sample container carriers, each being adapted to carry one or more sample containers, each sample container carrier comprising at least one magnetically active device, - a transport plane, being adapted to support the sample container carriers, - a number of electro-magnetic actuators, being stationary arranged below the transport plane, the electro-magnetic actuators being adapted to move the sample container carriers on top of the transport plane by applying a magnetic force to the sample container carriers, - a number of sensors being distributed over the transport plane, and - a control unit, being configured to control the movement of the sample container carriers on top of the transport plane using signals provided by the sensors by driving the electro-magnetic actuators such that the sample container carriers move along corresponding transport paths, characterized in that - the number of sensors are magnetic sensors, and - the laboratory sample distribution system further comprises: - a calibration device (10, 50), wherein the calibration device (10, 50) comprises - a magnetic calibration element (30, 70) causing a magnetic calibration field, and - drive means (20, 60, 80) adapted to change a distance between the magnetic calibration element (30, 70) and a respective magnetic sensor, - position determining means (40, 170, 175) adapted to determine the distance between the magnetic calibration element (30, 70) and a respective magnetic sensor, and - a calibration control unit, - wherein the calibration control unit is configured to monitor signals received from the magnetic sensors while the distance between the magnetic calibration element (30, 70) and a respective magnetic sensor is changed, and - wherein the calibration control unit is configured to determine magnetic sensor parameters for each of the magnetic sensors in response to the signals received from the magnetic sensors and the determined distance. - a number of sample container carriers, each being adapted to carry one or more sample containers, each sample container carrier comprising at least one magnetically active device, - a transport plane, being adapted to support the sample container carriers, - a number of electro-magnetic actuators, being stationary arranged below the transport plane, the electro-magnetic actuators being adapted to move the sample container carriers on top of the transport plane by applying a magnetic force to the sample container carriers, - a number of sensors being distributed over the transport plane, and - a control unit, being configured to control the movement of the sample container carriers on top of the transport plane using signals provided by the sensors by driving the electro-magnetic actuators such that the sample container carriers move along corresponding transport paths, characterized in that - the number of sensors are magnetic sensors, and - the laboratory sample distribution system further comprises: - a calibration device (10, 50), wherein the calibration device (10, 50) comprises - a magnetic calibration element (30, 70) causing a magnetic calibration field, and - drive means (20, 60, 80) adapted to change a distance between the magnetic calibration element (30, 70) and a respective magnetic sensor, - position determining means (40, 170, 175) adapted to determine the distance between the magnetic calibration element (30, 70) and a respective magnetic sensor, and - a calibration control unit, - wherein the calibration control unit is configured to monitor signals received from the magnetic sensors while the distance between the magnetic calibration element (30, 70) and a respective magnetic sensor is changed, and - wherein the calibration control unit is configured to determine magnetic sensor parameters for each of the magnetic sensors in response to the signals received from the magnetic sensors and the determined distance. - a calibration device (10, 50), wherein the calibration device (10, 50) comprises - a magnetic calibration element (30, 70) causing a magnetic calibration field, and - drive means (20, 60, 80) adapted to change a distance between the magnetic calibration element (30, 70) and a respective magnetic sensor, - a magnetic calibration element (30, 70) causing a magnetic calibration field, and - drive means (20, 60, 80) adapted to change a distance between the magnetic calibration element (30, 70) and a respective magnetic sensor, - position determining means (40, 170, 175) adapted to determine the distance between the magnetic calibration element (30, 70) and a respective magnetic sensor, and - a calibration control unit, - wherein the calibration control unit is configured to monitor signals received from the magnetic sensors while the distance between the magnetic calibration element (30, 70) and a respective magnetic sensor is changed, and - wherein the calibration control unit is configured to determine magnetic sensor parameters for each of the magnetic sensors in response to the signals received from the magnetic sensors and the determined distance. - wherein the calibration control unit is configured to monitor signals received from the magnetic sensors while the distance between the magnetic calibration element (30, 70) and a respective magnetic sensor is changed, and - wherein the calibration control unit is configured to determine magnetic sensor parameters for each of the magnetic sensors in response to the signals received from the magnetic sensors and the determined distance.