The T78 is a new approach to measure, record and analyse power quality on electrical installations. Thanks to an innovative design and a graphic colour TFT “touch screen” wide display this model finally meets all requests from any electrical verifier. The interface is “user-friendly” due to the intuitive icon selection of any kind of feature and a contextual help is available for each screen. Each internal parameter is easy to reach due to the typical Windows tree structure. Each model permits the visualisation of all parameters both in numeric and graphical mode with large use of waveforms and histograms (for harmonic analysis) screens. The vectorial diagram feature allows the user to evaluate the mutual phase angle between voltages and current in order to understand the inductive or capacitive nature of the loads on an installation.