The Evaluation of Adulteration in Milk Using The Propagation of Ultrasonic Waves

Milk testing is needed to find out if the milk is still pure or already contains harmful mixed substances in order to avoid the harmful effects that endanger the consumer. Among the many testing methods, there are non-destructive, in-situ, and rapid testing techniques, namely the ultrasonic wave transmission testing. Continuous ultrasonic waves of 1 MHz frequency generated from a transmitter transducer are routed to the whole milk medium in a test cell with a transducer distance of 9.3 mm and received by a receiver transducer placed facing each other. Milk content uses three types of substances namely water, liquid sugar, and coconut milk with a concentration variation of 0-55.9 wt%. Attenuation is calculated by comparing the amplitude of the receiver's ultrasonic waves with the transmitter. Wave velocity is measured by differences in sinusoid ultrasonic wavelengths between receiver and transmitter. The results of this study showed that there is a strong correlation that is directly proportional between wave velocity transmission and the coefficient of attenuation on the concentration of adulterated milk. From the correlation obtained non-destructive testing methods using ultrasonic wave transmission can be done and developed.