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 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.