Development of Water Concentration Sensor in Fresh Milk Products Based on Capacitance

Milk is one of the main commodities of Indonesian society. However, there is a gap between the amount of production and milk needs, giving rise to the possibility of supplementing milk with non-dairy fluids. The mixture generally used for milk is the addition of water. Design for a sensor to detect water concentration in fresh milk products using capacitance measurements was developed. Capacitive sensors work based on the capacitance concept based on changes in the dielectric constant. The sensor design includes a specially designed capacitive sensor in the form of a parallel plate with a rectangular cross-sectional area of 4.7 cm², with a sensor height of 3 cm and a width of 1.6 cm and a distance between the two plates of 0.4 cm. Signal conditioners are used to convert sensor output into a frequency response. The result show the relationship between milk purity concentration and frequency output has a linear relationship with the equation f=196205 – 228C with linearity coefficient R² = 0.961.