The article contains the results of research within the project to apply unipolar (axial) flux to obtain diagnostic signals carrying the information of: electrical asymmetries of machinery (inter-turn stator short-circuits, cage damages); rotational speed of the rotor and load torque. Inter-turn stator short-circuits can be detected both at starting process time (when they appear most often), as well as in steady states. Detection of rotor cage defects in steady states has a character of a comparative study, and over time, as the defects develop. For standard drives that are powered from the network and work in open systems, by measuring the voltage following a unipolar flux, it is possible to make measurement and recording of motor speed, which usually is almost never provided under industrial conditions. The study shows that a simple in its construction, cheap coil can be a very useful diagnostic tool. The measurements were carried out at the laboratory and motor workplace in the power plant, while in the test station, during the loading, characteristics illustrating the dependence of the torque on the axial flux and on the rotational speed were obtained. A way of using a single measurement to estimate the torque has been proposed. The method is relatively simple to implement and allows for a fully non-invasive determination of the load torque.