Application of plastic optical fiber as a calcium and pH sensor for milk quality review

Calcium and pH sensors based on plastic optical fibers (POF) using a spiral spring configuration that variation the number of winding with the addition of imperfections has been made. Application of the sensor is done by immersing the sensor into a sample of calcium and pH content that have varying concentrations and values. Experimental measurements show the relationship between variations in calcium content and pH values on the output voltage. The magnitude of changes in the value of calcium and pH in milk produces a small output voltage. The sensor shows a high sensitivity value and the best resolution in a spiral spring configuration with 5 windings and 5 imperfections added. The maximum sensitivity value in the measurement of milk calcium is 0.0018 V I mg.L−1 and resolution 0.5488 mg.L−1, while the measurement of pH of milk obtained a sensitivity of 0.0448 VIpH, and a resolution of 0.0223 pH. Milk calcium and pH sensors offered have an effective method, a simple design, more economical, high sensitivity and good resolution. Milk calcium and pH sensors offered have an effective method, a simple design, more economical, high sensitivity and good resolution.