Inclusive Technology in Chemistry: Validation of an Arduino Talking pH Meter

Abstract

The present study shows the assembly and design of a talking pH meter on the Arduino platform, with the aim of promoting inclusion in chemistry laboratories for students with visual impairments. The equipment uses a pH-4502C module, an E201-BNC electrode, and a DS18B20 temperature sensor, mounted on an Arduino UNO development board. An audio system with speakers was implemented to communicate pH and temperature measurements simultaneously, thus facilitating the inclusion of visually impaired students. The performance of the Arduino-based equipment was evaluated with respect to the Orion Star A111 commercial pH meter through calibration analysis, weighted linear regression, and ANOVA tests with pH 4.00, 7.00, and 10.00 buffer solutions. The results showed very good linearity (r² > 0.998), with slopes of -59.03 mV/pH (Arduino) and -58.6 mV/pH (A111), and efficiencies of 99.78% and 99.39%, respectively. Statistical tests show no significant differences between both devices (Fcal < Ftab), although greater dispersion was detected in the readings of the Arduino system in alkaline conditions, attributable to the ADC resolution and absence of automatic temperature compensation. However, the prototype meets the accuracy requirements for academic purposes, representing a viable, accessible, and inclusive alternative for the development of experimental skills in inclusive educational environments.