FIELD: chemical engineering; spectroscopy. SUBSTANCE: method involves passing photon beam through multiphase liquid of variable salinity. Radiation absorption level is measured at least at three radiation power levels. The so obtained data are sent to data processing unit that gives data output concerning the liquid composition including those of salt if available, by using phase fraction calculation algorithm taking into account radiation absorption caused by salt. EFFECT: enhanced accuracy of measurements; salt component calculation; simplified measuring instrument calibration. 8 cl, 2 dwg, 2 tbl
