In this study, different configurations based on linear fiber lasers were proposed and experimentally demonstrated to measure the concentration of liquid solutions. Samples of paracetamol liquid solutions with different concentrations, in the range from 52. 33 g/kg, were used as a. This work reports an optical fiber–based continuous liquid level sensor for cryogenic propellant mass gauging, which has significant advantages over the existing liquid level sensors in terms of accuracy, simplicity, and reliability. Based on Rayleigh backscattering coherent optical frequency. OFS is currently employed to sense physical and chemical characteristics, namely light intensity, vibration, temperature, pressure, strain, liquid level, pH, chemical analysis, concentration, density, refractive index of liquids, etc. It offers a number of advantages including spark free, low. 1Maestría en Física Aplicada, Escuela de Posgrado, Pontificia Universidad Católica del Perú, Lima, Perú. Baldwin, "Liquid concentration measurements with fiber optic sensor," in Latin America Optics and Photonics Conference, OSA Technical Digest (Optica. Liquid concentration measurement would provide indirect clues for liquid quality monitoring for safeguarding human health. The salinity of liquid is a very important parameter for Mariculture, prediction of climatic changes, Oceanic, marine liquid monitoring, drinking liquid monitoring similarly. In this paper, a novel liquid level sensing system is proposed to enhance the capacity of the sensing system, as well as reduce the cost and increase the sensing accuracy.