Continuous pH control plays a key role in many sectors, such as agriculture, food processing, chemical production, and water‑quality testing. In hydroponics, for example, accurate pH control is fundamental to maintain nutrient solutions suitable for plant growth. However, while many sensors are available for occasional or manual pH checks, robust solutions for real-time and continuous monitoring are still largely missing. The main objective of this thesis is to develop the prototype of a compact pH‑measurement system, designed for continuous operation and suitable for in-field operation. The proposed device relies on fluorescence analysis, exploiting the relationship between the fluorescence peak of a suitable fluorophore and pH.