Use of low-cost sensor as an alternative for ph monitoring in hydroponic system - DOI: 10.7127/rbai.v1901388

Resumo

Hydroponics has become increasingly popular due to its production potential and for offering several advantages such as efficient use of water and use of reduced space for cultivation. However, to ensure proper functioning of this system, monitoring some parameters, such as the pH of the solution, is indispensable. Data were collected during the growing cycle of hydroponic lettuce. The alternative pH sensor (pH-4502C) was calibrated relative to simultaneous readings with a standard sensor (benchtop), by means of polynomial regression, and the model that best fitted the data was chosen based on the highest value of the coefficient of determination (R2). The calibration equation showed R2 of 0.72, and significantly improved the accuracy of the sensor, reducing the RMSE value by 30%, making its performance change from “average” to “very good”. The calibration of the pH sensor (pH-4502C) enhanced its use in low-cost nutrient solution monitoring systems for hydroponic cultivation. The calibration equation improved the capacity of the sensor to predict pH values,so its use without prior calibration is not recommended.