The Study Effect of Temperature and Path Length on the Optical Transmittance Spectrum in Different Water Medias

Abstract

This research aims to study the effect of temperature and optical path length on optical transmittance in water media with different concentrations -achieved by adding salt and maalox [〖Mg(OH)〗_2 and 〖Al(OH)〗_3]. the laboratory setup consists of visible lasers with different wavelengths, including: laser He-Ne with a wavelength of 632.8 nm and a power of 5 mW, red laser with a wavelength of 635 nm and power of 100 mW, green laser with a wavelength of 532 nm and a power of 200 mW and a blue laser with a wavelength of 445 nm and a power of 100 mW. The laser beam passes through a glass water basin a distance of 50 cm to reach a photodetector  that measures the optical power in mW to calculate the optical transmittance.

The experimental results of this work indicated that: The optical transmittance of all the wavelengths considered decreases in the aqueous medium with the increase in the water temperature and the increase in the length of the optical path, and that the process of the decrease in the optical transmittance depends on the wavelength of the laser used.