Design of a Tea Polyphenols Concentration Detector for Tea Health Food Applications

In this work, a tea polyphenols concentration detector is proposed for tea health food applications innovatively. The proposed detector includes a tea polyphenols sensor and a converter that can convert tea polyphenols concentrations into a linear frequency output. Furthermore, the proposed converter designed as a multistage relaxation oscillator is to provide higher sensitivity for adaptive utilization in different tea polyphenols concentrations. The measured input range of the converter was 0.2-2.2 V, and the corresponding range of the frequency output was 3.639-18.14 MHz. The sensitivity was 7.25 MHz/V. The measured range of tea polyphenols concentrations was 0.6-2.8 x 10(-3) mol/L, and the frequency output was ranged from 8.79 to 13.11 MHz. A 0.27% of the measured maximum linear error was ensured. Finally, a test of green tea was successfully experimented. Confirmations through results, the tea polyphenols concentration detector could have normal functions for tea health food applications.