Design of a measurement device explaining the relationship between the concentration of solution and the light absorbance for chemical education

This research aims to study about developing and demonstrating the low-cost and portable light absorbance measurement device for using and learning in analytical experiments. The spectrophotometer is important for analytical chemistry to measure the concentration of solution. In chemical analysis, the UV-spectrophotometer is used to measure the solution for collecting the light absorbance from the solution. In chemical education, the spectrophotometer is used for studying about relationship between the concentration of solution and light absorbance by Beer's law. However, nowadays the spectrophotometer is expensive to purchase many devices for every students learning. The UV-spectrophotometer has many functions which are not necessary in education. To support the chemistry education, we develop the low-cost spectrophotometer for chemistry education by using easy parts and decreasing the unnecessary functions. We check the quality of the proposed device by comparing the coefficient of determination between the spectrophotometer and the proposed device. After checking the efficiency of the proposed device, we check the measurement of red solution by changing the red light intensity and found the weak point of the proposed device. The proposed device shows that the proposed device can explain the result similar with the spectrophotometer. Moreover, the excel program can receive and collect the data from the many proposed devices by a wireless network. The excel program can calculate the coefficient of determination and linear regression for finding the unknown concentration of solution.