With Tesla being the SI unit for magnetic field strength and the
documentatoin of the dal also declaring the output values as being
nanoteslas it is likely that this means this converts the magnetometer
raw data to nanoteslas (This is also the only way the values im
measuring with my lsm303agr are explainable).
commit be8451e723c0021e53d7eb7160ed534bd1abe1a1 introduced the scaling factor of 150 from the microbit codal by lancaster university. This factor is however explicitly mentioned to be a conversion factor to SI units here: https://github.com/lancaster-university/microbit-dal/blob/master/inc/drivers/LSM303Magnetometer.h#L36
With Tesla being the SI unit for magnetic field strength and the documentatoin of the dal also declaring the output values as being nanoteslas it is likely that this means this converts the magnetometer raw data to nanoteslas (This is also the only way the values im measuring with my lsm303agr are explainable).