method of measuring the flow-rate in wich a tracer of known concentration is injected at a constant and known flow-rate at one cross-section of the conduit and its dilution is measured at another cross-section downsstream where a spefified level of mixing has taken place, vedeliku voo/voomahu mõõtemeetod, mille puhul teadaoleva kontsentratsiooniga märgistusainet süstitakse konstantse ja teadaoleva vedeliku vookiirusega toru ühte ristlõikesse ning selle lahjendust mõõdetakse toru teises ristlõikes allavoolu, kus on toimunud kindlaksmääratud segunemise tase.