A novel method for inspecting raw milk quality by using dual-coil inductance

Abstract

This paper presents a novel inspection method that uses dual-coil inductance to evaluate the quality of raw milk. The device contains a silicon-based chip with two co-planar coils, which is fabricated by using a simple microelectroplating process. Based on the phase variation between both coils, the quality of the raw milk, in terms of the somatic cell count (SCC), can be evaluated, because the milk from a cow that suffers from mastitis is a better conductor of electric current. In this study, the sensing performance was evaluated by experiment. The experimental results show that the raw milk with higher SSCs cause larger phase shifts. For a typical fabrication result, the measurement sensitivity in terms of SCC is 3°/log(SCC) at an excitation frequency of 9 MHz. The proposed dual-coil chip reduces size and cost and has a rapid response, which allows efficient quality inspection of raw milk.