This thesis discusses technical improvements done at a sodium lithium mixtures experiment, to enable measurements highly sensitive on the magnetic field. An active magnetic field stabilisation for low magnetic fields of less then one gauss was tested and added to the experiment. The focus was put on the suppression of field oscillations from the power lines, cancellation of external influences and long term stability. The prototype configuration and its performance is then reviewed and possible future improvements are discussed. For precise atom population measurements a new control and readout camera software was written and implemented. A systematic evaluation of the settings was performed and subsequently used to optimise the lithium imaging.