Refractometric Fiber Optic Sensor for Detecting Salinity of Water

Abstract

Salinity is an important property of industrial and natural waters. It is defined as the measure of the mass of dissolved salts in a given mass of solution. High salinity has an impact on people and industries reliant on water. High levels of salt can reduce crop yields, limit the choice of crops that can be grown and, at higher concentrations over long periods, can kill trees and make the land unsuitable for agricultural purposes. Salinity increases the "hardness" of water, which can mean more soap and detergents have to be used or water softeners installed and maintained. This can also cause scaling in pipes and heaters. The experimental determination of the salt content by drying and weighing presents some difficulties due to the loss of some components. The only reliable way to determine the true or absolute salinity of natural water is to make a complete chemical analysis. However, the method is time consuming and cannot yield the precision necessity for accurate work. Thus to determine salinity, one normally used method involves the measurement of a physical property such as conductivity, density or refractive index. The paper reports the refractometric fiber optic sensor for detection of salinity of water. The mathematical model is developed for detection of the refractive index of liquid and simulated in MATLAB. The fiber optic sensor probe is developed to measure the refractive index of the solution containing different amount of salt dissolved in water i.e. different molar concentrations. Experiments are carried out using the developed probe for these solutions. Experimental results are showing good agreement with the simulated results.

Fiber-Optic Chemical Sensors and Biosensors (2013–2015)

“…Sensors for salinity and ionic strength are needed in marine sciences, during blood dialysis, in the chemical and nuclear industry in general, and in agriculture, in particular in arid areas. The salinity of water slightly affects its RI, and a refractometric FOCS was developed on the basis of this principle . A mathematical model was developed to simulate the sensor response, and the concentration of NaCl in water can be measured in the 0.02 to 0.5 M range.…”

Modeling, Simulation and Experimental Studies of Refractometric Fiber Optic Sensor

“…Experiments are set to verify the simulated models for measuring the adulteration of diesel by kerosene. Figure 7 shows block diagram of instrument along with sensor probe [6]- [12]. It consists of light source and its driving circuit, photo-detector and its driving circuit, sensor probe and chemical cell.…”

Fiber Optic Displacement Sensor for Honey Purity Detection Using Glucose Adulterant

“…Over the past two decades, the use of fiber optic sensors for contaminant detection in food stuff has need widely exploited. Fiber optic sensor offer simplicity, low cost and non-contact type sensing which able to perform without contacting the sample [5]. The honey sensor is applied using the beam-through technique whereby light is transmitted through transmitting fiber to a receiving fiber and the received light is measured by a photodetector [6].…”