Research Paper: Optical Properties of Algae in Order to Design and Build a Device for Measuring the Amount of Chlorophyll in Water Reservoirs Using the Optical Fluorescence Emission Method

In this article, we will first get acquainted with the absorption and emission optical properties of algae and types of chlorophylls, and then we will examine the optical setup for measuring the photoluminescence light produced by algae, which is the basis for the construction of chlorophyll concentration measuring devices. By examining algae samples in fresh water ponds in Iran and identifying the predominant type of algae in them, spectrometry and concentration measurement were carried out with the help of hemocytometer or neobar lam method. The most important tool for measuring the concentration of algae is chlorophyll-a, which is present in all types of algae with different percentages and has the property of fluorescence, and by measuring the red light resulting from photoluminescence, the amount of chlorophyll-a can be obtained. The main design of a device to measure the amount of chlorophyll-a based on the measurement of photoluminescence light is considered for this purpose and it is used in terms of software and hardware. For this, the process and intensity of light in terms of density was done for calibration, and the disadvantages and advantages of the design were examined. Direct measurement of light, noises, high stability and preparing a logical routine between the data can help to increase and improve the quality and this device becomes a precise tool for measuring chlorophyll and has commercialization capabilities. The stability, reproducibility and high accuracy of the device is one of the advantages of emission (photoluminescence) test methods compared to absorbance methods.