DESIGN OF CAPACITIVE SENSORS FOR CHARACTERIZATION OF MILK DRINKS

• Main Author: Pamungkas, Gigih
• Format: Theses
• Language: Indonesia
• Subjects: Fisika
• Online Access: https://digilib.itb.ac.id/gdl/view/38174
• Institution: Institut Teknologi Bandung

The decrease in milk quality is largely influenced by the presence of microorganisms and their metabolic activities. Its existence needs to be monitored to determine the level of quality of the milk. The use of capacitive sensors to detect changes in the state of milk has been developed. The measured capacitance is related to the size of the permittivity or dielectric of the milk sampled. The purpose of this study is to design an instrument system to determine changes in milk quality and determine changes in milk capacitance values in the event of a decrease in quality. This experimental method is measuring milk capacitance in room temperature in real time during a certain time using a capacitive sensor instrument and LCR meter as a comparison. In addition, data collection of sterile milk samples was also carried out using electrochemical impedance spectroscopy as supporting data. The results of monitoring raw milk using both capacitive sensor instruments and LCR meters began to decrease the capacitance value after 1 hour and were seen flat in the next 4 hours. The decrease in capacitance is supported by data from LCR meter capacitance measurements carried out for 6 hours where it appears that the capacitance drops from 11.97 ?F to 10.32 ?F and 3.87 nF to 2.25 nF by measuring capacitive sensor instruments. The decrease in capacitance during the monitoring process is due to a decrease in the dielectric constant of the milk during the process of quality degradation. In addition, it is also suspected because of the increase in the number of bacteria in milk which results in a decrease in the milk capacitance value.