Open AccessDevelopment of an optical pH measurement system based on colorimetric effect
Author(s) -
Puteri Nur Syahirah Mohamed Mustafa,
Aiman Shahmi Azam,
Mohd Suhaimi Sulaiman,
Ahmad Omar,
Mohamad Faizal Abd Rahman
Publication year - 2021
Publication title -
indonesian journal of electrical engineering and computer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.241
H-Index - 17
eISSN - 2502-4760
pISSN - 2502-4752
DOI - 10.11591/ijeecs.v24.i2.pp728-735
Subject(s) - photodiode , absorbance , usb , reagent , analytical chemistry (journal) , light intensity , chemistry , reliability (semiconductor) , accuracy and precision , measure (data warehouse) , system of measurement , reproducibility , correlation coefficient , calibration , software , materials science , computer science , optics , optoelectronics , chromatography , mathematics , physics , statistics , quantum mechanics , database , programming language , astronomy , machine learning , power (physics)
This paper proposed an optical pH measurement system developed to measure the changes of pH levels based on colorimetric reactions with phenol red reagent. The optical sensing was achieved through the implementation of a pair of light emitting diode (LED) and photodiode. The detection mechanism was based on different absorbance of light intensity at pH values of 2.36, 8.32, 9.08 and 12.83. The data processing method was carried out using LabVIEW software and interfaced with NI USB DAQ 6008. The measured voltage showed a good correlation in relation to the pH level with R2 equals to 0.9624. This relationship was used as a calibration curve in the final system testing. The final measurement of pH showed a good agreement between the actual and measured values with an error of less than 5%, thus indicating the reliability of the proposed system.