Summary:

In the paper, problems of measuring of water usage in the aspect of possibilities of running water loss limitation were exposed. It has been proved that badly selected or of outdated construction water-meter, may influence the value of real and virtual water loss. Introduction of measurement of water usage’s amount has two very important aspects. First: by limitation of water wastage, it causes rationalisation of its usage, and second: it enables accounting amount of water used by locators by walking away from the ineffective and sometimes unfair lump payment collection. Moreover, in the paper short characteristic of water-meters occurring on the market was shown, regarding their division, basic parameters and metrological classes. The most important problems of water-meters’ usage in household architecture were discussed. It has been ascertained, that the causes of water losses, apart from the physical water wastage because of leakages, are measurement errors and water stealing, which directly or indirectly are results of applied mensuration equipment. Examples of interference with installation and water-meters were quoted and possibilities of their limitations were shown. Practical advice was given, which will help to avoid problems with the correct measurement of water usage’s amount. At the end, new trends in mensuration of water usage were shown, which aim at using modern, unfailing and very exact water-meters, automatisation of readings and remote data transfer from the gauge to the main computer without necessity of people’s participation. It was stated, that the modern water-meter construction isn’t the whole key to success. Very important is its correct choice (regarding nominal flow), installation and exploitation. Only fulfillment of these conditions, will let minimalise measurement errors and limit water stealing, and what comes after that, decrease of running water loss index.