DESIGN OF ELECTRIC CONDUCTIVITY MONITORING TOOL USING TWO PROBE WITH ALTERNATING CURRENT (AC) BASED ON ARDUINO MICROCONTROLLER TO MEASURE THE EFFECT OF ULTRAVIOLET RAY ON MILK QUALITY

• Main Author: Wildany, Dany
• Format: Theses
• Language: Indonesia
• Subjects: Fisika
• Online Access: https://digilib.itb.ac.id/gdl/view/41355
• Institution: Institut Teknologi Bandung

An electrical conductivity monitoring device has been designed using two arduino microcontroller-based ac current probes. This study aims to analyze the effect of ultraviolet (UV) rays on electrical conductivity, pH and temperature which are indicators of milk quality. Electrical conductivity tool used is a gravity tds meter v.1.0 dfrobot with two AC current probes. The electrical conductivity, ph and temperature sensors are connected to the Arduino UNO microcontroller which stores the results of the data on a computer. Calibration by the factory using a standard buffer solution of 707ppm (1413?S / cm) at a temperature of 250 c. Recalibration was carried out using a standard buffer solution of 1408ppm (2816 ?S / cm) at a temperature of 26o c. Preliminary data from measurements of temperature, real conductivity, corrected conductivity and sequential pH in UHT milk samples not given UV (non-UV samples) are temperatures 25.5oC, real conductivity (25.5oC) 2827 ?S / cm, corrected conductivity (250C) and pH 6.5 While the initial data samples that will be given UV (UV samples) sequentially are 25.5oC, real conductivity (25.5oC) 2827?S / cm, corrected conductivity (25oC) 2792?S / cm and pH 6.5. After being given UV light for 6 hours, obtained non-UV samples increased in temperature by 27.2oC, real conductivity tended to remain (2827-2838 ?S / cm), corrected conductivity decreased (2808-2717?S / cm), and pH tended to decrease (6.5- 6.3) while the UV sample has increased temperature (25.5-30.7oC), real conductivity remains (2827?S / cm), corrected conductivity decreases (2788-2538?S / cm) and pH remains constant (6.5). After the UV light is turned off and the sample is left for 12 hours the temperature, real conductivity, corrected conductivity and pH of the non-UV samples are 26.5oC, 2827?S / cm-3838?S / cm, 2749-2757, and pH 4.8, while the UV sample is obtained 26oC, 2827?S / cm, 2772?S / cm, and pH 5.1. The decrease in pH occurs faster in non-UV samples (6.5 to 4.8 in 18 hours) than UV samples (6.5 to 5.1 in 18 hours) which shows a decrease in milk quality in non-UV samples faster than UV samples.