Selecting the right averaging period is not easy. To a large extent it depends on the type of disturbance in the system and the user’s expectations for the final data analysis. A typical situation is that we only know that there is a problem in the mains, and the measurements with the analyser will only help us identify the cause. In this situation it is better to use shorter averaging times (e.g. 10 seconds), and activate the recording of minimum and maximum values (for the voltages and currents it is advisable in such situation to set the shortest possible time for determining the maximum and minimum value, i.e. half the period). Short time averaging will give more precise diagrams of changes of the parameters over time, and minimums and maximums will be detected and recorded. Recording with short averaging times is only recommended for limited time period as large amounts of data will be collected quickly and is not a suitable for a long-term analysis or survey.